Most spreadsheet programs have a rather nice little built-in function called NETWORKDAYS to calculate the number of business days (i.e. Monday-Friday, excluding holidays) between any two given dates. I couldn't find a simple way to do that in PHP, so I threw this together. It replicates the functionality of OpenOffice's NETWORKDAYS function - you give it a start date, an end date, and an array of any holidays you want skipped, and it'll tell you the number of business days (inclusive of the start and end days!) between them.
I've tested it pretty strenuously but date arithmetic is complicated and there's always the possibility I missed something, so please feel free to check my math.
The function could certainly be made much more powerful, to allow you to set different days to be ignored (e.g. "skip all Fridays and Saturdays but include Sundays") or to set up dates that should always be skipped (e.g. "skip July 4th in any year, skip the first Monday in September in any year"). But that's a project for another time.
<?php
function networkdays($s, $e, $holidays = array()) {
// If the start and end dates are given in the wrong order, flip them.
if ($s > $e)
return networkdays($e, $s, $holidays);
// Find the ISO-8601 day of the week for the two dates.
$sd = date("N", $s);
$ed = date("N", $e);
// Find the number of weeks between the dates.
$w = floor(($e - $s)/(86400*7)); # Divide the difference in the two times by seven days to get the number of weeks.
if ($ed >= $sd) { $w--; } # If the end date falls on the same day of the week or a later day of the week than the start date, subtract a week.
// Calculate net working days.
$nwd = max(6 - $sd, 0); # If the start day is Saturday or Sunday, add zero, otherewise add six minus the weekday number.
$nwd += min($ed, 5); # If the end day is Saturday or Sunday, add five, otherwise add the weekday number.
$nwd += $w * 5; # Add five days for each week in between.
// Iterate through the array of holidays. For each holiday between the start and end dates that isn't a Saturday or a Sunday, remove one day.
foreach ($holidays as $h) {
$h = strtotime($h);
if ($h > $s && $h < $e && date("N", $h) < 6)
$nwd--;
}
return $nwd;
}
$start = strtotime("1 January 2010");
$end = strtotime("13 December 2010");
// Add as many holidays as desired.
$holidays = array();
$holidays[] = "4 July 2010"; // Falls on a Sunday; doesn't affect count
$holidays[] = "6 September 2010"; // Falls on a Monday; reduces count by one
echo networkdays($start, $end, $holidays); // Returns 246
?>
Or, if you just want to know how many work days there are in any given year, here's a quick function for that one:
<?php
function workdaysinyear($y) {
$j1 = mktime(0,0,0,1,1,$y);
if (date("L", $j1)) {
if (date("N", $j1) == 6)
return 260;
elseif (date("N", $j1) == 5 or date("N", $j1) == 7)
return 261;
else
return 262;
}
else {
if (date("N", $j1) == 6 or date("N", $j1) == 7)
return 260;
else
return 261;
}
}
?>
date
(PHP 4, PHP 5)
date — Dar formato a la fecha/hora local
Descripción
$format
[, int $timestamp = time()
] )
Devuelve una cadena formateada según el formato dado usando el
parámetro de tipo integer timestamp dado o el momento actual
si no se da una marca de tiempo. En otras palabras, timestamp
es opcional y por defecto es el valor de time().
Parámetros
-
format -
El formato de la fecha de salida tipo string. Vea las opciones de formato más abajo. También hay varias constantes de fecha predefinidas que pueden usarse en su lugar, así por ejemplo
DATE_RSScontiene la cadena de formato 'D, d M Y H:i:s'.Los siguientes caracteres están reconocidos en el parámetro de cadena formatCarácter de formatDescripción Ejemplo de valores devueltos Día --- --- d Día del mes, 2 dígitos con ceros iniciales 01 a 31 D Una representación textual de un día, tres letras Mon hasta Sun j Día del mes sin ceros iniciales 1 a 31 l ('L' minúscula) Una representación textual completa del día de la semana Sunday hasta Saturday N Representación numérica ISO-8601 del día de la semana (añadido en PHP 5.1.0) 1 (para lunes) hasta 7 (para domingo) S Sufijo ordinal inglés para el día del mes, 2 caracteres st, nd, rd o th. Funciona bien con j w Representación numérica del día de la semana 0 (para domingo) hasta 6 (para sábado) z El día del año (comenzando por 0) 0 hasta 365 Semana --- --- W Número de la semana del año ISO-8601, las semanas comienzan en lunes (añadido en PHP 4.1.0) Ejemplo: 42 (la 42ª semana del año) Mes --- --- F Una representación textual completa de un mes, como January o March January hasta December m Representación numérica de una mes, con ceros iniciales 01 hasta 12 M Una representación textual corta de un mes, tres letras Jan hasta Dec n Representación numérica de un mes, sin ceros iniciales 1 hasta 12 t Número de días del mes dado 28 hasta 31 Año --- --- L Si es un año bisiesto 1 si es bisiesto, 0 si no. o Número de año ISO-8601. Esto tiene el mismo valor que Y, excepto que si el número de la semana ISO (W) pertenece al año anterior o siguiente, se usa ese año en su lugar. (añadido en PHP 5.1.0) Ejemplos: 1999 o 2003 Y Una representación numérica completa de un año, 4 dígitos Ejemplos: 1999 o 2003 y Una representación de dos dígitos de un año Ejemplos: 99 o 03 Hora --- --- a Ante meridiem y Post meridiem en minúsculas am o pm A Ante meridiem y Post meridiem en mayúsculas AM o PM B Hora Internet 000 hasta 999 g Formato de 12 horas de una hora sin ceros iniciales 1 hasta 12 G Formato de 24 horas de una hora sin ceros iniciales 0 hasta 23 h Formato de 12 horas de una hora con ceros iniciales 01 hasta 12 H Formato de 24 horas de una hora con ceros iniciales 00 hasta 23 i Minutos, con ceros iniciales 00 hasta 59 s Segundos, con ceros iniciales 00 hasta 59 u Microsegundos (añadido en PHP 5.2.2). Observe que date() siempre generará 000000 ya que toma un parámetro de tipo integer, mientras que DateTime::format() admite microsegundos. Ejemplo: 654321 Zona Horaria --- --- e Identificador de zona horaria (añadido en PHP 5.1.0) Ejemplos: UTC, GMT, Atlantic/Azores I (i mayúscula) Si la fecha está en horario de verano o no 1 si está en horario de verano, 0 si no. O Diferencia de la hora de Greenwich (GMT) en horas Ejemplo: +0200 P Diferencia con la hora de Greenwich (GMT) con dos puntos entre horas y minutos (añadido en PHP 5.1.3) Ejemplo: +02:00 T Abreviatura de la zona horaria Ejemplos: EST, MDT ... Z Índice de la zona horaria en segundos. El índice para zonas horarias al oeste de UTC siempre es negativo, y para aquellas al este de UTC es siempre positivo. -43200 hasta 50400 Fecha/Hora Completa --- --- c Fecha ISO 8601 (añadido en PHP 5) 2004-02-12T15:19:21+00:00 r Fecha con formato » RFC 2822 Ejemplo: Thu, 21 Dec 2000 16:01:07 +0200 U Segundos desde la Época Unix (1 de Enero del 1970 00:00:00 GMT) Vea también time() Los caracteres no reconocidos en la cadena de formato serán impresos tal cual. El formato Z siempre devolverá 0 cuando se usa gmdate().
Nota:
Ya que esta función sólo acepta marcas de tiempo de tipo integer el carácter de formato u sólo es útil cuando se usa la función date_format() con marcas de tiempo basadas en usuario creadas con date_create().
-
timestamp -
El parámetro opcional
timestampes una marca de tiempo Unix de tipo integer que por defecto es la hora local si no se proporciona ningún valor atimestamp. En otras palabras, es por defecto el valor de la función time().
Valores devueltos
Devuelve una cadena de fecha formateada. Si se usa un valor no numérico para
timestamp, se devuelve FALSE y
se emite un error de nivel E_WARNING.
Errores/Excepciones
Cada vez que se llame a la función date/time se generará un E_NOTICE
si la zona horaria no es válida, y/o un mensaje E_STRICT
o E_WARNING
si se usa la configuración del sistema o la variable global
TZ. Vea también date_default_timezone_set()
Historial de cambios
| Versión | Descripción |
|---|---|
| 5.1.0 | El rango válido de una marca de tiempo es típicamente desde Fri, 13 Dec 1901 20:45:54 GMT a Tue, 19 Jan 2038 03:14:07 GMT. (Estas son las fechas que corresponden a los valores mínimo y máximo de un entero con signo de 32 bit). Sin embargo, antes de PHP 5.1.0 este rango estaba limitado desde 01-01-1970 a 19-01-2038 en algunos sistemas (p.ej. Windows). |
| 5.1.0 |
Ahora muestra |
| 5.1.1 |
Hay constantes útiles
de formatos de fecha/hora estándar que se pueden usar para especificar el
parámetro format.
|
Ejemplos
Ejemplo #1 Ejemplo de date()
<?php
// Establecer la zona horaria predeterminada a usar. Disponible desde PHP 5.1
date_default_timezone_set('UTC');
// Imprime algo como: Monday
echo date("l");
// Imprime algo como: Monday 8th of August 2005 03:12:46 PM
echo date('l jS \of F Y h:i:s A');
// Imprime: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " . date("l", mktime(0, 0, 0, 7, 1, 2000));
/* Usar las constantes en el parámetro de formato */
// Imprime algo como: Mon, 15 Aug 2005 15:12:46 UTC
echo date(DATE_RFC822);
// Imprime algo como: 2000-07-01T00:00:00+00:00
echo date(DATE_ATOM, mktime(0, 0, 0, 7, 1, 2000));
?>
Puede prevenir que un carácter reconocido en la cadena de formato sea expandido escapándolo con una barra invertida precedente. Si el carácter con una barra invertida es ya una secuencia especial, necesitará escapar también la barra invertida.
Ejemplo #2 Escapar caracteres en date()
<?php
// imprime algo como: Wednesday the 15th
echo date('l \t\h\e jS');
?>
Es posible usar date() y mktime() juntos para buscar fechas en el futuro o en el pasado.
Ejemplo #3 Ejemplo de date() y mktime()
<?php
$mañana = mktime(0, 0, 0, date("m") , date("d")+1, date("Y"));
$mes_anterior = mktime(0, 0, 0, date("m")-1, date("d"), date("Y"));
$año_siguiente = mktime(0, 0, 0, date("m"), date("d"), date("Y")+1);
?>
Nota:
Esto puede ser más fiable que añadir o sustraer simplemente el número de segundos de un día o mes a una marca de tiempo debido al horario de verano.
Algunos ejemplos de formatear date(). Observe que debería escapar cualesquiera otros caracteres, ya que cualquiera que tenga actualmente un significado especial producirá resultados no deseados, y a otros caracteres se les pueden asignar significado en futuras versiones de PHP. Cuando se escapa un carácter, asegúrese de usar comillas simples para prevenir que caracteres como \n se conviertan en nuevas líneas.
Ejemplo #4 date() Formatting
<?php
// Se asume que hoy es March 10th, 2001, 5:16:18 pm, y que estamos en la
// zona horaria Mountain Standard Time (MST)
$hoy = date("F j, Y, g:i a"); // March 10, 2001, 5:16 pm
$hoy = date("m.d.y"); // 03.10.01
$hoy = date("j, n, Y"); // 10, 3, 2001
$hoy = date("Ymd"); // 20010310
$hoy = date('h-i-s, j-m-y, it is w Day'); // 05-16-18, 10-03-01, 1631 1618 6 Satpm01
$hoy = date('\i\t \i\s \t\h\e jS \d\a\y.'); // it is the 10th day.
$hoy = date("D M j G:i:s T Y"); // Sat Mar 10 17:16:18 MST 2001
$hoy = date('H:m:s \m \i\s\ \m\o\n\t\h'); // 17:03:18 m is month
$hoy = date("H:i:s"); // 17:16:18
$hoy = date("Y-m-d H:i:s"); // 2001-03-10 17:16:18 (el formato DATETIME de MySQL)
?>
Para formatear fechas en otros lenguajes debería usar las funciones setlocale() y strftime() en vez de date().
Notas
Nota:
Para generar una marca de tiempo desde una cadena que representa la fecha, puede usar strtotime(). Adicionalmente, algunas bases de datos tienen funciones para convertir formatos de fecha en marcas de tiempo (como la función » UNIX_TIMESTAMP de MySQL).
La marca de tiempo del inicio de una petición está disponible en $_SERVER['REQUEST_TIME'] desde PHP 5.1.
Ver también
- gmdate() - Formatea una fecha/hora GMT/UTC
- idate() - Formatea una fecha/hora local como un entero
- getdate() - Obtener información de la fecha/hora
- getlastmod() - Obtiene la hora de la última modificación de la página
- mktime() - Obtener la marca de tiempo Unix de una fecha
- strftime() - Formatea una fecha/hora local según la configuración regional
- time() - Devuelve la fecha Unix actual
- strtotime() - Convierte una descripción de fecha/hora textual en Inglés a una fecha Unix
- Constantes Predefinidas de DateTime
If you want to compare this week with the same week last year, here is some code to get you the time at the beginning of the week. You can then add days, hours, etc to get to the day of the week that you want to know about.
<?php
$time_passed = (date('N')-1)* 24 * 3600; // time since start of week in days
$startOfWeek = mktime(0,0,0,date('m'),date('d'),date('Y')) - $time_passed;
$lastyear = $startOfWeek - 365*24*3600;
// make sure time used from last year is the same week of the year
$weekdiff = date('W') - date('W',$lastyear);
if($weekdiff != 0)
{
$lastyear = $lastyear + ($weekdiff*7*24*3600);
}
$lastyear_time_passed = (date('N',$lastyear)-1) * 24 * 3600; // time since start of week in days
$startOfWeek_lastyear = mktime(0,0,0,date('m',$lastyear),date('d',$lastyear),date('Y',$lastyear)) - $lastyear_time_passed;
?>
So now you have the unix time for the start of this week ($startOfWeek), and the start of the same week last year ($startOfWeek_lastyear).
You can convert back to datetime format easily:
<?php
echo date('Y-m-d H:i:s',$startOfWeek).'<br>';
echo date('Y-m-d H:i:s',$startOfWeek_lastyear).'<br><br>';
echo date('l F jS, Y',$startOfWeek).'<br>';
echo date('l F jS, Y',$startOfWeek_lastyear);
?>
To actually make use ot the "u" (microsecond) you need to use the DateTime object and not the date() function.
For example
<?php
$t = microtime(true);
$micro = sprintf("%06d",($t - floor($t)) * 1000000);
$d = new DateTime( date('Y-m-d H:i:s.'.$micro,$t) );
print $d->format("Y-m-d H:i:s.u");
?>
<?php
/* the following variables are set to appropriate
characters recognized by php version 5 that
will get the date. To display the date, we have
to use 'echo' or 'print' to send the variable
data to the browser
*/
$day=date("l");
$date=date("j");
$suffix=date("S");
$month=date("F");
$year=date("Y");
echo $day . ", " . $month . " " . $date . $suffix . ", " . $year;
?>
rudimentary, simple way to due things, but it gets the job done for someone learning more on the subject.
The following function will return the date (on the Gregorian calendar) for Orthodox Easter (Pascha). Note that incorrect results will be returned for years less than 1601 or greater than 2399. This is because the Julian calendar (from which the Easter date is calculated) deviates from the Gregorian by one day for each century-year that is NOT a leap-year, i.e. the century is divisible by 4 but not by 10. (In the old Julian reckoning, EVERY 4th year was a leap-year.)
This algorithm was first proposed by the mathematician/physicist Gauss. Its complexity derives from the fact that the calculation is based on a combination of solar and lunar calendars.
<?php
function getOrthodoxEaster($date){
/*
Takes any Gregorian date and returns the Gregorian
date of Orthodox Easter for that year.
*/
$year = date("Y", $date);
$r1 = $year % 19;
$r2 = $year % 4;
$r3 = $year % 7;
$ra = 19 * $r1 + 16;
$r4 = $ra % 30;
$rb = 2 * $r2 + 4 * $r3 + 6 * $r4;
$r5 = $rb % 7;
$rc = $r4 + $r5;
//Orthodox Easter for this year will fall $rc days after April 3
return strtotime("3 April $year + $rc days");
}
?>
I've been flicking through the comments looking for some succinct date code and have noticed an alarming number of questions and over-burdened examples related to date mathematics. One of the most useful skills you can utilize when performing date math is taking full advantage of the UNIX timestamp. The UNIX timestamp was built for this kind of work.
An example of this relates to a comment made by james at bandit-dot-co-dot-en-zed. James was looking for a way to calculate the number of days which have passed since a certain date. Rather than using mktime() and a loop, James can subtract the current timestamp from the timestamp of the date in question and divide that by the number of seconds in a day:
<?php
$days = floor((time() - strtotime("01-Jan-2006"))/86400);
print("$days days have passed.\n");
?>
Another usage could find itself in a class submitted by Kyle M Hall which aids in the creation of timestamps from the recent past for use with MySQL. Rather than the looping and fine tuning of a date, Kyle can use the raw UNIX timestamps (this is untested code):
<?php
$ago = 14; // days
$timestamp = time() - ($ago * 86400);
?>
Hopefully these two examples of "UNIX-style" timestamp usage will help those finding date mathematics more elusive than it should be.
here is an example how you can make numeric days of the week from 1 to 7(Monday to Friday)
<?php
$currentdate = mktime(0, 0, 0, date("m") , date("d"), date("Y"));
echo $day_eg1 = date ('N',$currentdate);
echo $day_eg2 = date("N", $today+1 * 24 * 3600);
echo $day_eg3= date("N", $today+2 * 24 * 3600);
echo $day_eg4 = date("N", $today+3 * 24 * 3600);
echo $day_eg5 = date("N", $today+4 * 24 * 3600);
echo $day_eg6 = date("N", $today+5 * 24 * 3600);
echo $day_eg7 = date("N", $today+6 * 24 * 3600);
?>
date("W") returns the iso8601 week number, while date("Y") returns the _current_ year. This can lead to odd results. For example today (dec 31, 2007) it returns 1 for the week and of course 2007 for the year. This is not wrong in a strict sense because iso defines this week as the first of 2008 while we still have 2007.
So, if you don't have another way to safely retrieve the year according to the iso8061 week-date - strftime("%G") doesn't work on some systems -, you should be careful when working with date("W").
For most cases strftime("%W") should be a safe replacement.
[edit: Much easier is to use "o" (lower case O) instead of "Y"]
If you want to find your server's timezone offset from GMT, it seems as though you could just do:
date('Z')
to get the number of seconds offset. But PHP requires that you call date_default_timezone_set(). So if you have to hard-code a timezone, why not simply hard-code a variable that tells you the offset from GMT? If you set the timezone to GMT, the dates in your database will still be in local time, but time('Z') will return zero.
To keep your code portable across servers in different timezones, you can do this:
date_default_timezone_set(date_default_timezone_get())
This keeps PHP from complaining that you haven't called date_default_timezone_set(), but makes your code portable. Ridiculous.
Not sure why this got ignored the first time, but this is an even simpler way to check leap year:
<?php
function isLeapYear($year)
{ return ((($year%4==0) && ($year%100)) || $year%400==0) ? (true):(false); }
?>
In order to determine if a year is a leap year an earlier poster suggested simply checking to see if the year is a multiple of four:
<?php
function is_leapyear_broken($year = 2004) {
return ($year%4)==0;
}
?>
While this will work for the majority of years it will not work on years that are multiples of 100 but not multiples of 400 i.e.(2100).
A function not using php's date() function that will also account for this small anomaly in leap years:
<?php
function is_leapyear_working($year = 2004) {
if((($year%4==0) && ($year%100!=0)) || $year%400==0) {
return true;
}
return false;
}
?>
While is_leapyear_working will not return true for the few non-leap years divisible by four I couldn't tell you if this is more or less efficient than using php's date() as an even earlier poster suggested:
<?php
function is_leapyear($year = 2004) {
$is_leap = date('L', strtotime("$year-1-1"));
return $is_leap;
}
?>
Use this to convert the local/UTC hour to the UTC/local hour:
<?php
for($utc_to_local = array(), $offset = date('Z'), $h = 0; $h < 24; $utc_to_local[] = date('G', mktime($h++)+$offset));
$local_to_utc = array_flip($utc_to_local);
echo "2 am local is ", $local_to_utc[2], " UTC";
echo "3 pm UTC is ", $utc_to_local[15], " local";
?>
This is useful when you need to do many conversions. Lookup tables are faster than calling date() and mktime() multiple times.
If you are having an issue getting u to work so is everyone else. The solution that I am using which I found on another site(so not taking credit) is to use this:
date("Y/m/d H:i:s"). substr((string)microtime(), 1, 6);
that will give you:
yyyy/mm/dd hh:ii:ss.uuuuuu
hope this helps someone in need!
thanks all
Thanks to tcasparr at gmail dot com for the great idea (at least for me) ;)
I changed the code a little to replicate the functionality of date_parse_from_format, once I don't have PHP 5.3.0 yet. This might be useful for someone. Hope you don't mind changing your code tcasparr at gmail dot com.
<?php
/*******************************************************
* Simple function to take in a date format and return array of associated
* formats for each date element
*
* @return array
* @param string $strFormat
*
* Example: Y/m/d g:i:s becomes
* Array
* (
* [year] => Y
* [month] => m
* [day] => d
* [hour] => g
* [minute] => i
* [second] => s
* )
*
* This function is needed for PHP < 5.3.0
********************************************************/
function dateParseFromFormat($stFormat, $stData)
{
$aDataRet = array();
$aPieces = split('[:/.\ \-]', $stFormat);
$aDatePart = split('[:/.\ \-]', $stData);
foreach($aPieces as $key=>$chPiece)
{
switch ($chPiece)
{
case 'd':
case 'j':
$aDataRet['day'] = $aDatePart[$key];
break;
case 'F':
case 'M':
case 'm':
case 'n':
$aDataRet['month'] = $aDatePart[$key];
break;
case 'o':
case 'Y':
case 'y':
$aDataRet['year'] = $aDatePart[$key];
break;
case 'g':
case 'G':
case 'h':
case 'H':
$aDataRet['hour'] = $aDatePart[$key];
break;
case 'i':
$aDataRet['minute'] = $aDatePart[$key];
break;
case 's':
$aDataRet['second'] = $aDatePart[$key];
break;
}
}
return $aDataRet;
}
?>
Also, if you need to change the format of dates:
<?php
function changeDateFormat($stDate,$stFormatFrom,$stFormatTo)
{
// When PHP 5.3.0 becomes available to me
//$date = date_parse_from_format($stFormatFrom,$stDate);
//For now I use the function above
$date = dateParseFromFormat($stFormatFrom,$stDate);
return date($stFormatTo,mktime($date['hour'],
$date['minute'],
$date['second'],
$date['month'],
$date['day'],
$date['year']));
}
?>
<?php
// A demonstration of the new DateTime class for those
// trying to use dates before 1970 or after 2038.
?>
<h2>PHP 2038 date bug demo (php version <?php echo phpversion(); ?>)</h1>
<div style='float:left;margin-right:3em;'>
<h3>OLD Buggy date()</h3>
<?php
$format='F j, Y';
for ( $i = 1900; $i < 2050; $i++) {
$datep = "$i-01-01";
?>
Trying: <?php echo $datep; ?> = <?php echo date($format, strtotime($datep)); ?><br>
<?php
}
?></div>
<div style='float:left;'>
<h3>NEW DateTime Class (v 5.2+)</h3><?php
for ( $i = 1900; $i < 2050; $i++) {
$datep = "$i-01-01";
$date = new DateTime($datep);
?>
Trying: <?php echo $datep; ?> = <?php echo $date->format($format); ?><br>
<?php
}
?></div>
Things to be aware of when using week numbers with years.
<?php
echo date("YW", strtotime("2011-01-07")); // gives 201101
echo date("YW", strtotime("2011-12-31")); // gives 201152
echo date("YW", strtotime("2011-01-01")); // gives 201152 too
?>
BUT
<?php
echo date("oW", strtotime("2011-01-07")); // gives 201101
echo date("oW", strtotime("2011-12-31")); // gives 201152
echo date("oW", strtotime("2011-01-01")); // gives 201052 (Year is different than previous example)
?>
Reason:
Y is year from the date
o is ISO-8601 year number
W is ISO-8601 week number of year
Conclusion:
if using 'W' for the week number use 'o' for the year.
Correct format for a MySQL DATETIME column is
<?php $mysqltime = date ("Y-m-d H:i:s", $phptime); ?>
If you want to use HTML5's <date> tag, the following code will generate the machine-readable value for the 'datetime' attribute:
<?php
/**
* formats the date passed into format required by 'datetime' attribute of <date> tag
* if no intDate supplied, uses current date.
* @param intDate integer optional
* @return string
**/
function getDateTimeValue( $intDate = null ) {
$strFormat = 'Y-m-d\TH:i:s.uP';
$strDate = $intDate ? date( $strFormat, $intDate ) : date( $strFormat ) ;
return $strDate;
}
echo getDateTimeValue();
?>
Sometimes it is very useful to convert a sql timestamp to an also called NTP time. This is often used as time date notation in XML RSS pages. To convert a timestamp to this NTP notation try the following:
<?php
echo date('D, d M Y h:i:s O', strtotime ($timestamp);
?>
this how you make an HTML5 <time> tag correctly
<?php
echo '<time datetime="'.date('c').'">'.date('Y - m - d').'</time>';
?>
in the "datetime" attribute you should put a machine-readable value which represent time , the best value is a full time/date with ISO 8601 ( date('c') ) ,,, the attr will be hidden from users
and it doesn't really matter what you put as a shown value to the user,, any date/time format is okay !
This is very good for SEO especially search engines like Google .
This function will add working day to a given timestamp
<?php
function addworkinday($timestamp,$daystoadd){
$dayoftheweek = date("N",$timestamp);
$sum =$dayoftheweek +$daystoadd;
while ($sum >= 6) {
$daystoadd=$daystoadd+1;
$sum=$sum-1;
}
return $timestamp +(60*60*24*$daystoadd);
}
?>
Here is a cool Date class to implement the date function:
<?php
/*
* @author Gchats
*
* Date class
*/
class Date
{
private $shortDateFormat = "F j, Y";
private $longDateFormat = "F j, Y, g:i a";
private $timestamp = 0;
/**
* Default constructor
*
* @param integer $timestamp unix time stamp
*/
function __construct($timestamp = 0)
{
$this->timestamp = $timestamp;
}
/**
* Returns the given timestamp in the constructor
*
* @return integer time stamp
*/
public function getTime()
{
return (int) $this->timestamp;
}
/*
* Returns long formatted date of the given timestamp
*
* @access public
* @return string Long formatted date
*/
public function long()
{
if ( $this->timestamp > 0 )
{
return date ( $this->longDateFormat , $this->timestamp );
}
else
{
return "";
}
}
/*
* Returns short formatted date of the given timestamp
*
* @access public
* @return string Short formatted date
*/
public function short()
{
if ( $this->timestamp > 0 )
{
return date ( $this->shortDateFormat , $this->timestamp );
}
else
{
return "";
}
}
public function __toString()
{
return $this->timestamp;
}
}
?>
Here's my solution for looking up the month number by name (used when parsing an 'ls'):
<?php
for($m=1;$m<=12;$m++){
$month=date("M",mktime(0,0,0,$m,1,2000));
$mon["$month"]=$m;
}
?>
I needed to convet a duration timestamp into H:i:s but whenever I did it kept bringing 5 back as 01:00:05 (due to some DST stuff) so I made this function to replace date(). It has no optimisations but hopefully someone might find it useful:
<?php
function get_time_string(){
$time = 3600+(60*32)+(50); // 01:32:50
$time_string = '';
$hours = (int)($time/(60*60));
if(strlen($hours) > 1){
$time_string = $hours.':';
}else{
$time_string = '0'.$hours.':';
}
$minutes = (int)(($time%(60*60))/(60));
if($minutes >= 1){
if(strlen($minutes) > 1){
$time_string .= $minutes.':';
}else{
$time_string .= '0'.$minutes.':';
}
$seconds = ($time%(60*60))%(60);
if(strlen($seconds) > 1){
$time_string .= $seconds;
}else{
$time_string .= '0'.$seconds;
}
}else{
if(strlen($time) > 1){
$time_string .= '00:'.$time;
}else{
$time_string .= '00:0'.$time;
}
}
return $time_string;
}
?>
Note that some formatting options are different from MySQL.
For example using a 24 hour notation without leading zeros is the option '%G' in PHP but '%k' in MySQL.
When using dynamically generated date formatting string, be careful to generate the correct options for either PHP or MySQL.
I use the function below to calculate the Unix timestamp of the start of a week. It includes a boolean flag to request a GMT offset instead of the current locale setting.
<?php
function getWeekOffsetTimestamp($year, $week, $useGmt = false) {
if ($useGmt) {
// Backup timezone and set to GMT
$timezoneSettingBackup = date_default_timezone_get();
date_default_timezone_set("GMT");
}
// According to ISO-8601, January 4th is always in week 1
$halfwayTheWeek = strtotime($year."0104 +".($week - 1)." weeks");
// Subtract days to Monday
$dayOfTheWeek = date("N", $halfwayTheWeek);
$daysToSubtract = $dayOfTheWeek - 1;
// Calculate the week's timestamp
$unixTimestamp = strtotime("-$daysToSubtract day", $halfwayTheWeek);
if ($useGmt) {
// Reset timezone to backup
date_default_timezone_set($timezoneSettingBackup);
}
return $unixTimestamp;
}
?>
<?php
/**
* Checks wether a date is between an interval
*
* Usage:
*
* // check if today is older than 2008/12/31
* var_dump(currentDayIsInInterval('2008/12/31'));
* // check if today is younger than 2008/12/31
* var_dump(currentDayIsInInterval(null,'2008/12/31'));
* // check if today is between 2008/12/01 and 2008/12/31
* var_dump(currentDayIsInInterval('2008/12/01','2008/12/31'));
*
* Will trigger errors if date is in wrong format, notices if $begin > $end
*
* @param string $begin Date string as YYYY/mm/dd
* @param string $end Date string as YYYY/mm/dd
* @return bool
*/
function currentDayIsInInterval($begin = '',$end = '')
{
$preg_exp = '"[0-9][0-9][0-9][0-9]/[0-9][0-9]/[0-9][0-9]"';
$preg_error = 'Wrong parameter passed to function '.__FUNCTION__.' : Invalide date
format. Please use YYYY/mm/dd.';
$interval_error = 'First parameter in '.__FUNCTION__.' should be smaller than
second.';
if(empty($begin))
{
$begin = 0;
}
else
{
if(preg_match($preg_exp,$begin))
{
$begin = (int)str_replace('/','',$begin);
}
else
{
trigger_error($preg_error,E_USER_ERROR);
}
}
if(empty($end))
{
$end = 99999999;
}
else
{
if(preg_match($preg_exp,$end))
{
$end = (int)str_replace('/','',$end);
}
else
{
trigger_error($preg_error,E_USER_ERROR);
}
}
if($end < $begin)
{
trigger_error($interval_error,E_USER_WARNING);
}
$time = time();
$now = (int)(date('Y',$time).date('m',$time).date('j',$time));
if($now > $end or $now < $begin)
{
return false;
}
return true;
}
?>
date() has some strange behavior at extremely high values:
<?php
echo "9223372036854775805: " . date("Y-m-d g:i:s a", 9223372036854775805) . "\n";
echo "9223372036854775806: " . date("Y-m-d g:i:s a", 9223372036854775806) . "\n";
echo "9223372036854775807: " . date("Y-m-d g:i:s a", 9223372036854775807) . " (0x7FFFFFFFFFFFFFFF)\n";
echo "9223372036854775808: " . date("Y-m-d g:i:s a", 9223372036854775808) . "\n";
echo "9223372036854775809: " . date("Y-m-d g:i:s a", 9223372036854775809) . "\n";
echo "9223372036854775810: " . date("Y-m-d g:i:s a", 9223372036854775810) . "\n";
echo "...\n";
echo "9223372036854776832: " . date("Y-m-d g:i:s a", 9223372036854776832) . "\n";
echo "9223372036854776833: " . date("Y-m-d g:i:s a", 9223372036854776833) . "\n";
echo "...\n";
echo "9223372036854778879: " . date("Y-m-d g:i:s a", 9223372036854778879) . "\n";
echo "9223372036854778880: " . date("Y-m-d g:i:s a", 9223372036854778880) . "\n";
echo "...\n";
echo "9223372036854780928: " . date("Y-m-d g:i:s a", 9223372036854780928) . "\n";
echo "9223372036854780929: " . date("Y-m-d g:i:s a", 9223372036854780929) . "\n";
echo "...\n";
echo "9223372036854782975: " . date("Y-m-d g:i:s a", 9223372036854782975) . "\n";
echo "9223372036854782976: " . date("Y-m-d g:i:s a", 9223372036854782976) . "\n";
echo "...\n";
echo "9223372036854785024: " . date("Y-m-d g:i:s a", 9223372036854785024) . "\n";
echo "9223372036854785025: " . date("Y-m-d g:i:s a", 9223372036854785025) . "\n";
echo "...\n";
echo "9223372036854787071: " . date("Y-m-d g:i:s a", 9223372036854787071) . "\n";
echo "9223372036854787072: " . date("Y-m-d g:i:s a", 9223372036854787072) . "\n";
echo "...\n";
echo "9223372036854789120: " . date("Y-m-d g:i:s a", 9223372036854789120) . "\n";
echo "9223372036854789121: " . date("Y-m-d g:i:s a", 9223372036854789121) . "\n";
echo "...\n";
echo "9223372036854791167: " . date("Y-m-d g:i:s a", 9223372036854791167) . "\n";
echo "9223372036854791168: " . date("Y-m-d g:i:s a", 9223372036854791168) . "\n";
echo "...\n";
echo "9223372036854793215: " . date("Y-m-d g:i:s a", 9223372036854793215) . "\n";
echo "9223372036854793216: " . date("Y-m-d g:i:s a", 9223372036854793216) . "\n";
echo "9223372036854793217: " . date("Y-m-d g:i:s a", 9223372036854793217) . "\n";
echo "9223372036854793218: " . date("Y-m-d g:i:s a", 9223372036854793218) . "\n";
?>
Output:
9223372036854775805: 292277026596-12-04 10:30:05 am
9223372036854775806: 292277026596-12-04 10:30:06 am
9223372036854775807: 292277026596-12-04 10:30:07 am (0x7FFFFFFFFFFFFFFF)
9223372036854775808: 292277026596-12-04 10:30:08 am
9223372036854775809: 292277026596-12-04 10:30:08 am
9223372036854775810: 292277026596-12-04 10:30:08 am
...
9223372036854778879: 292277026596-12-04 10:30:08 am
9223372036854778880: 292277026596-12-04 11:04:16 am
...
9223372036854778879: 292277026596-12-04 11:04:16 am
9223372036854778880: 292277026596-12-04 11:38:24 am
...
9223372036854780928: 292277026596-12-04 11:38:24 am
9223372036854780929: 292277026596-12-04 12:12:32 pm
...
9223372036854782975: 292277026596-12-04 12:12:32 pm
9223372036854782976: 292277026596-12-04 12:46:40 pm
...
9223372036854785024: 292277026596-12-04 12:46:40 pm
9223372036854785025: 292277026596-12-04 1:20:48 pm
...
9223372036854787071: 292277026596-12-04 1:20:48 pm
9223372036854787072: 292277026596-12-04 1:54:56 pm
...
9223372036854789120: 292277026596-12-04 1:54:56 pm
9223372036854789121: 292277026596-12-04 2:29:04 pm
...
9223372036854791167: 292277026596-12-04 2:29:04 pm
9223372036854791168: 292277026596-12-04 3:03:12 pm
...
9223372036854793215: 292277026596-12-04 3:03:12 pm
9223372036854793216: 292277026596-12-04 3:03:12 pm
9223372036854793217: -292277022657-01-27 8:37:04 am
9223372036854793218: -292277022657-01-27 8:37:04 am
---
So, the last reliable unix timecode is 9223372036854775808 (0x1000000000000000). Not that you would probably ever need a date that high.
Just lately I have been wanting to convert a Unix Timestamp into a readable date and time, and there's not many places around that can help you to archive this, so here is a bit of code that will allow you to convert the Unix Timestamp into a more more readable date and time.
<?php
// Get the timestamp
$timestamp = "1340892242";
// Convert the timestamp
$date = date("D, d M Y", $timestamp);
$time = date("H:i:s", $timestamp);
// Echo out the timestamp
echo "<strong>Date: </strong>".$date."<br/ >";
echo "<strong>Time: </strong>".$time;
?>
=================
RESULT
=================
Date: Thu, 28 Jun 2012
Time: 09:04:02
=================
It was oblivious and discouraging that it dont mentioned in docs. If you will use W to get week number be aware:
first days of year can be in a week of previous year, and week number always has leading zero
<?php
echo date("YW", strtotime("2011-01-07")); // gives 201101
echo date("YW", strtotime("2011-01-01")); // gives 201152
echo date("YW", strtotime("2011-12-31")); // gives 201152 too
?>
so you can`t rely on number of week given from this function inside your program if you want to use it for some logic
To find last sunday for given date
<?php
$day = '2012-10-04';
echo 'last sunday : '.date("Y-m-d",strtotime($day." last Sunday "));
?>
output:
last sunday : 2012-09-30
If anyone needs a really fast function for converting a datetime string (i.e. as retrieved from a MySQL DATETIME entry) into a human-friendly time output analogous to date($format, $time), here's a useful function.
<?
function fdate($datetimestring = '1970-01-01 00:00:00', $format = 'U') {
// Create a datetime object, return it formatted
// If you want to give credit for this somewhere, thanks.
// You really don't have to though; this is kinda obvious
$dt = new DateTime($datetimestring);
return $dt->format($format);
}
?>
The main purpose of this is to reduce lines of code and allow inline coding. For example:
<?
/* ... */
echo "This page was submitted on ".fdate($row['created'], 'F j, Y g:i:s A')." and last modified ".fdate($row['modified'], 'F j, Y g:i:s A')."<br />\n";
/* ... */
?>
