date

(PHP 3, PHP 4 )

date -- Format a local time/date

string date ( string format [, int timestamp])

Returns a string formatted according to the given format string using the given integer timestamp or the current local time if no timestamp is given. In otherwords, timestamp is optional and defaults to the value of time().

注: The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer). On windows this range is limited from 01-01-1970 to 19-01-2038.

To generate a timestamp from a string representation of the date, you may be able to use strtotime(). Additionally, some databases have functions to convert their date formats into timestamps (such as MySQL's UNIX_TIMESTAMP function).



表格 1. The following characters are recognized in the format parameter string

Day of the month, 2 digits with leading zeros
A textual representation of a week, three letters
A full textual representation of a month, such as January or March
I (capital i) 1 if Daylight Savings Time, 0 otherwise.
l (lowercase 'L')
Whether it's a leap year 1 if it is a leap year, 0 otherwise.
Numeric representation of a month, with leading zeros
A short textual representation of a month, three letters
Numeric representation of a month, without leading zeros
Difference to Greenwich time (GMT) in hours Example: +0200
Example: Thu, 21 Dec 2000 16:01:07 +0200
Seconds, with leading zeros
English ordinal suffix for the day of the month, 2 characters st, nd, rd or th. Works well with j
Examples: EST, MDT ...
Seconds since the Unix Epoch (January 1 1970 00:00:00 GMT) See also time()
0 (for Sunday) through 6 (for Saturday)
ISO-8601 week number of year, weeks starting on Monday (added in PHP 4.1.0) Example: 42 (the 42nd week in the year)
A full numeric representation of a year, 4 digits Examples: 1999 or 2003
Examples: 99 or 03
Timezone offset in seconds. The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.


Unrecognized characters in the format string will be printed as-is. The Z format will always return 0 when using gmdate().

範例 1. date() examples

 ?php
// Prints something like: Wednesday
echo date("l");

// Prints something like: Wednesday 15th of January 2003 05:51:38 AM
echo date ("l dS of F Y h:i:s A");

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


You can prevent a recognized character in the format string from being expanded by escaping it with a preceding backslash. If the character with a backslash is already a special sequence, you may need to also escape the backslash.

範例 2. Escaping characters in date()

 ?php
// prints something like: Wednesday the 15th
echo date("l \\t\h\e jS");
? 


It is possible to use date() and mktime() together to find dates in the future or the past.

範例 3. date() and mktime() example

 ?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);
? 

注: This can be more reliable than simply adding or subtracting the number of seconds in a day or month to a timestamp because of daylight savings time.



Some examples of date() formatting. Note that you should escape any other characters, as any which currently have a special meaning will produce undesirable results, and other characters may be assigned meaning in future PHP versions. When escaping, be sure to use single quotes to prevent characters like \n from becoming newlines.

範例 4. date() Formatting

 ?php
// Assuming today is: March 10th, 2001, 5:16:18 pm

$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 z ');  // 05-16-17, 10-03-01, 1631 1618 6 Fripm01
$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 15:16:08 MST 2001
$today = date('H:m:s \m \i\s\ \m\o\n\t\h');     // 17:03:17 m is month
$today = date("H:i:s");                         // 17:16:17
? 


To format dates in other languages, you should use the setlocale() and strftime() functions.

See also getlastmod(), gmdate(), mktime(), strftime() and time().