date

(PHP 4, PHP 5, PHP 7, PHP 8)

date — Formatta un timestamp Unix

Descrizione

date(string $format, ?int $timestamp = null): string

Restituisce una stringa formattata in accordo con il formato della stringa data usando l'intero timestamp dato (timestamp Unix) o l'orario corrente se nessun timestamp è dato. In altre parole, timestamp è opzionale e di default prende il valore di time().

Avviso

I timestamp Unix non gestiscono i fusi orari. Utilizzare la classe DateTimeImmutable, e i suoi metodi di formattazione DateTimeInterface::format() per formattare le informazioni data/ora con un fuso orario allegato.

Elenco dei parametri

format: Formato accettato da DateTimeInterface::format().
timestamp: Il parametro opzionale timestamp è un integer timestamp Unix che ha come default l'ora locale attuale se un timestamp non è fornito. In altre parole, ha come default il valore di time().

Valori restituiti

Restituisce una stringa data formattata. Se viene utilizzato un valore non numerico per timestamp, viene restituito false e viene emesso un errore di livello E_WARNING.

Errori/Eccezioni

Ogni chiamata a una funzione data/ora genera un E_NOTICE se il time zone non è valido, e/o un messaggio E_STRICT o E_WARNING se si usano le impostazioni di sistema o la variabile d'ambiente TZ. Vedere anche date_default_timezone_set()

Log delle modifiche

Versione	Descrizione
8.0.0	`timestamp` ora è nullable.

Esempi

Example #1 Esempi di date()

<?php
// imposta il fuso orario di default da utilizzare.
date_default_timezone_set('UTC');


// Stampa qualcosa di simile a: Monday
echo date("l");

// Stampa qualcosa di simile a: Monday 8th of August 2005 03:12:46 PM
echo date('l jS \of F Y h:i:s A');

// Stampa: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " . date("l", mktime(0, 0, 0, 7, 1, 2000));

/* usa le costanti nel parametro format */
// stampa qualcosa di simile a: Wed, 25 Sep 2013 15:28:57 -0700
echo date(DATE_RFC2822);

// stampa qualcosa di simile a: 2000-07-01T00:00:00+00:00
echo date(DATE_ATOM, mktime(0, 0, 0, 7, 1, 2000));
?>

È possibile evitare che un carattere riconosciuto nella stringa formato venga espanso effettuando l'escape di esso anteponendo un backslash. Se il carattere con un backslash è già una sequenza speciale, potrebbe essere necessario effettuare l'escape anche del backslash.

Example #2 Effettuare l'escape dei caratteri in date()

<?php
// stampa qualcosa di simile a: Wednesday the 15th
echo date('l \t\h\e jS');
?>

È possibile utilizzare insieme date() e mktime() per trovare date nel futuro o nel passato.

Example #3 Esempio di date() e di mktime()

<?php
$tomorrow  = mktime(0, 0, 0, date("m")  , date("d")+1, date("Y"));
$lastmonth = mktime(0, 0, 0, date("m")-1, date("d"),   date("Y"));
$nextyear  = mktime(0, 0, 0, date("m"),   date("d"),   date("Y")+1);
?>

Nota:
Questo può essere più affidabile rispetto che semplicemente aggiungere o sottrarre il numero di secondi in un giorno o in un mese ad un timestamp a causa dell'ora legale.

Alcuni esempi della formattazione date(). Notare che si dovrebbe effettuare l'escape di qualsiasi altro carattere, come tutti quelli che attualmente hanno un significato speciale produrranno risultati indesiderati, e ad altri caratteri potrebbe essere assegnato un significato nelle versioni future di PHP. Quando si effettua l'escape, assicurarsi di usare gli apici singoli in modo da evitare che i caratteri come \n divengano nuove linee.

Example #4 Formattazione di date()

<?php
// Assumendo che oggi sia Il 10 Marzo, 2001, 5:16:18 pm, e che noi siamo nel
// Fuso Orario Mountain Standard Time (MST)

$today = date("F j, Y, g:i a");                 // March 10, 2001, 5:16 pm
$today = date("m.d.y");                         // 03.10.01
$today = date("j, n, Y");                       // 10, 3, 2001
$today = date("Ymd");                           // 20010310
$today = date('h-i-s, j-m-y, it is w Day');     // 05-16-18, 10-03-01, 1631 1618 6 Satpm01
$today = date('\i\t \i\s \t\h\e jS \d\a\y.');   // it is the 10th day.
$today = date("D M j G:i:s T Y");               // Sat Mar 10 17:16:18 MST 2001
$today = date('H:m:s \m \i\s\ \m\o\n\t\h');     // 17:03:18 m is month
$today = date("H:i:s");                         // 17:16:18
$today = date("Y-m-d H:i:s");                   // 2001-03-10 17:16:18 (the MySQL DATETIME format)
?>

Per formattare le date in altri lingue, può essere utilizzata IntlDateFormatter::format() al posto di date().

Note

Nota:
Per generare un timestamp da una stringa che rappresenta la data, si può essere in grado di utilizzare strtotime(). Inoltre, alcuni database hanno delle funzioni per convertire i loro formati data in timestamp (come la funzione » UNIX_TIMESTAMP di MySQL).

Suggerimento

Il timestamp dell'inizio della richiesta è disponibile in $_SERVER['REQUEST_TIME'].

Vedere anche:

DateTimeImmutable::__construct() - Returns new DateTimeImmutable object
DateTimeInterface::format() - Returns date formatted according to given format
gmdate() - Formatta una data/ora GMT/UTC
idate() - Format a local time/date part as integer
getdate() - Restituisce informazioni sulla data/orario
getlastmod() - Restituisce la data dell'ultima modifica alla pagina
mktime() - Restituisce la UNIX timestamp per una data
IntlDateFormatter::format() - Format the date/time value as a string
time() - Restituisce l'attuale UNIX timestamp
Costanti di DateTime Predefinite

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User Contributed Notes 21 notes

down

120

Jimmy ¶

12 years ago


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.

down

ivijan dot stefan at gmail dot com ¶

9 years ago


If you have a problem with the different time zone, this is the solution for that.
<?php
// first line of PHP
$defaultTimeZone='UTC';
if(date_default_timezone_get()!=$defaultTimeZone)) date_default_timezone_set($defaultTimeZone);

// somewhere in the code
function _date($format="r", $timestamp=false, $timezone=false)
{
    $userTimezone = new DateTimeZone(!empty($timezone) ? $timezone : 'GMT');
    $gmtTimezone = new DateTimeZone('GMT');
    $myDateTime = new DateTime(($timestamp!=false?date("r",(int)$timestamp):date("r")), $gmtTimezone);
    $offset = $userTimezone->getOffset($myDateTime);
    return date($format, ($timestamp!=false?(int)$timestamp:$myDateTime->format('U')) + $offset);
}

/* Example */
echo 'System Date/Time: '.date("Y-m-d | h:i:sa").'<br>';
echo 'New York Date/Time: '._date("Y-m-d | h:i:sa", false, 'America/New_York').'<br>';
echo 'Belgrade Date/Time: '._date("Y-m-d | h:i:sa", false, 'Europe/Belgrade').'<br>';
echo 'Belgrade Date/Time: '._date("Y-m-d | h:i:sa", 514640700, 'Europe/Belgrade').'<br>';
?>
This is the best and fastest solution for this problem. Working almost identical to date() function only as a supplement has the time zone option.

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adityabhai at gmail dot com ¶

11 years ago


For Microseconds, we can get by following:

echo date('Ymd His'.substr((string)microtime(), 1, 8).' e');

Thought, it might be useful to someone !

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FiraSEO ¶

11 years ago


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 .

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remindfwd at gmail dot com ¶

2 years ago


To get one month back, then simply write:

```
$oneMonthBack = date( DateTime::ISO8601, strtotime('-1 month' )); 
```

// results (for eg.)
// 2021-12-21T13:44:05+0000

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Bas Vijfwinkel ¶

12 years ago


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.

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SpikeDaCruz ¶

18 years ago


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");

}

?>

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Anonymous ¶

10 years ago


It's common for us to overthink the complexity of date/time calculations and underthink the power and flexibility of PHP's built-in functions.  Consider http://php.net/manual/en/function.date.php#108613

<?php
function get_time_string($seconds)
{
    return date('H:i:s', strtotime("2000-01-01 + $seconds SECONDS"));
}

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matthew dot hotchen at worldfirst dot com ¶

10 years ago


FYI: there's a list of constants with predefined formats on the DateTime object, for example instead of outputting ISO 8601 dates with:

<?php
echo date('c');
?>

or

<?php
echo date('Y-m-d\TH:i:sO');
?>

You can use

<?php
echo date(DateTime::ISO8601);
?>

instead, which is much easier to read.

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-1

bruslbn at gmail dot com ¶

6 years ago


In order to define leap year you must considre not only that year can be divide by 4!

The correct alghoritm is:

if (year is not divisible by 4) then (it is a common year)
else if (year is not divisible by 100) then (it is a leap year)
else if (year is not divisible by 400) then (it is a common year)
else (it is a leap year)

So the code should look like this:

if($year%4 == 0 && $year%100 != 0) {
    $leapYear = 1;
} elseif($year%400 == 0) {
    $leapYear = 1;                           
} else {
    $leapYear = 0;
}

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-2

ghotinet ¶

13 years ago


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;
    }
}

?>

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-6

Charlie ¶

8 years ago


For HTML5 datetime-local HTML input controls (http://www.w3.org/TR/html-markup/input.datetime-local.html) use format example: 1996-12-19T16:39:57

To generate this, escape the 'T', as shown below:

<?php
date('Y-m-d\TH:i:s');
?>

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-6

mirco dot babin at gmail dot com ¶

5 years ago


One important thing you should remember is that the timestamp value returned by time() is time-zone agnostic and gets the number of seconds since 1 January 1970 at 00:00:00 UTC. This means that at a particular point in time, this function will return the same value in the US, Europe, India, Japan, ...

date() will format a time-zone agnostic timestamp according to the default timezone set with date_default_timezone_set(...). Local time. If you want to output as UTC time use:

<?php
function dateUTC($format, $timestamp = null)
{
    if ($timestamp === null) $timestamp = time();

    $tz = date_default_timezone_get();
    date_default_timezone_set('UTC');

    $result = date($format, $timestamp);

    date_default_timezone_set($tz);
    return $result;
}
/>

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-9

david dot thomas at elliott-thomas dot com dot au ¶

8 years ago


Prior to PHP 5.6.23,  Relative Formats for the start of the week aligned with PHP's (0=Sunday,6=Saturday). Since 5.6.23,  Relative Formats for the start of the week align with ISO-8601 (1=Monday,7=Sunday). (http://php.net/manual/en/datetime.formats.relative.php)

This can produce different, and seemingly incorrect, results depending on your PHP version and your choice of 'w' or 'N' for the Numeric representation of the day of the week: 

<?php
echo "Today is Sun 2 Oct 2016, day ",date('w',strtotime('2016-10-02'))," of this week. ";  
echo "Day ",date('w',strtotime('2016-10-02 Monday next week'))," of next week is ",date('d M Y',strtotime('2016-10-02 Monday next week')),"<br />";

echo "Today is Sun 2 Oct 2016, day ",date('N',strtotime('2016-10-02'))," of this week. ";  
echo "Day ",date('w',strtotime('2016-10-02 Monday next week'))," of next week is ",date('d M Y',strtotime('2016-10-02 Monday next week'));
?> 

Prior to PHP 5.6.23, this results in: 

Today is Sun 2 Oct 2016, day 0 of this week. Day 1 of next week is 10 Oct 2016
Today is Sun 2 Oct 2016, day 7 of this week. Day 1 of next week is 10 Oct 2016

Since PHP 5.6.23, this results in: 

Today is Sun 2 Oct 2016, day 0 of this week. Day 1 of next week is 03 Oct 2016
Today is Sun 2 Oct 2016, day 7 of this week. Day 1 of next week is 03 Oct 2016

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-8

rc at macshot dot de ¶

7 years ago


At least in PHP 5.5.38 date('j.n.Y', 2222222222) gives a result of 2.6.2040.

So date is not longer limited to the minimum and maximum values for a 32-bit signed integer as timestamp.

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-10

Anonymous ¶

8 years ago


If timestamp is a string, date converts it to an integer in a possibly unexpected way:

<?php
echo (int)'0x10'; //0
echo intval('0x10'); //0
echo date('s', '0x10'); //gives 16
//however, no octal conversion:
echo date('s', '010'); //gives 10
?>

(PHP 5.6.16)

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-7

Jaap ¶

4 years ago


For users looking to format a unix timestamp with microseconds to mysql datetime, this function should do the trick:
<?php
        function sqlDateTimeFromMicroTimestamp(int $microtimestamp):string{
            $dt = new \DateTimeImmutable(); 
            $normalTimestamp = (int)floor($microtimestamp / 1000000);
            $sqlTimestampWithoutMicroseconds = $dt->setTimestamp($normalTimestamp)->format('Y-m-d H:i:s');
            $sqlTimestampWithMicroseconds = $sqlTimestampWithoutMicroseconds . '.'. ($microtimestamp % 1000000);
            return $sqlTimestampWithMicroseconds;
        }
?>

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-13

bruslbn at gmail dot com ¶

6 years ago


In order to define leap year you must considre not only that year can be divide by 4!

The correct alghoritm is:

if (year is not divisible by 4) then (it is a common year)
else if (year is not divisible by 100) then (it is a leap year)
else if (year is not divisible by 400) then (it is a common year)
else (it is a leap year)

So the code should look like this:

if($year%4 == 0 && $year%100 != 0) {
    $leapYear = 1;
} elseif($year%400 == 0) {
    $leapYear = 1;                           
} else {
    $leapYear = 0;
}

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-8

mparsa1372 at gmail dot com ¶

3 years ago


The example below formats today's date in three different ways:

<?php
echo "Today is " . date("Y/m/d") . "<br>";
echo "Today is " . date("Y.m.d") . "<br>";
echo "Today is " . date("Y-m-d") . "<br>";
echo "Today is " . date("l");
?>

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-21

bruslbn at gmail dot com ¶

6 years ago


In order to define leap year you must considre not only that year can be divide by 4!

The correct alghoritm is:

if (year is not divisible by 4) then (it is a common year)
else if (year is not divisible by 100) then (it is a leap year)
else if (year is not divisible by 400) then (it is a common year)
else (it is a leap year)

So the code should look like this:

if($year%4 == 0 && $year%100 != 0) {
    $leapYear = 1;
} elseif($year%400 == 0) {
    $leapYear = 1;                           
} else {
    $leapYear = 0;
}

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-28

arth dot inbox at gmail dot com ¶

5 years ago


Looks like date('u') is not microseconds, but is positive difference from rest part.

php > echo (DateTime::createFromFormat('U.u', '-128649659.999998'))->format('Y-m-d H:i:s.u U.u');
1965-12-03 23:59:01.999998 -128649659.999998

`U.u` parsed and formatted same, but means not 1965-12-03 23:59:00.000002.
Other words correct timestamp for example above is (-128649659 + 0.999998).  

Less confusing format for it is:  

php > echo DateTime::createFromFormat('U\+0.u', '-128649660+0.000002')->format('Y-m-d H:i:s.u');
1965-12-03 23:59:00.000002

Is that bug or feature?

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