Quick reference to the Date and Time functions of PHP.
| Function | Returns | Does what |
|---|---|---|
| checkdate(month, day, year) | Boolean | Validates date |
| date(format [, timestamp]) | String | Formats a time/date |
| date_sun_info(time , latitude , longitude) | Array | Returns sunset, sunrise, and twilight times |
| date_sunrise(timestamp [, format [, latitude [, longitude [, zenith [, $gmt_offset]]]]]) | Mixed | Returns time of sunrise for day and location |
| date_sunset(timestamp [, format [, latitude [, longitude [, zenith [, $gmt_offset]]]]]) | Mixed | Returns time of sunset for day and location |
| getdate([timestamp]) | Array | Returns date/time settings for timestamp |
| gettimeofday([return_float]) | Mixed | Returns array for current time, or optional float |
| gmdate(format [, timestamp]) | String | Formats a GMT date/time |
| gmmktime([hour [, minute [, second [, month [, day [, year [, is_dst]]]]]]]) | Integer | Returns UNIX timestamp for GMT time/date. Default current date. |
| gmstrftime(format [, timestamp]) | String | Formats a GMT date/time as per current locale |
| localtime([timestamp[, is_associative]) | Array | Returns local time as array |
| microtime([get_as_float]) | Mixed | Returns microseconds from epoch. String or float. |
| mktime([hour [, minute [, second [, month [, day [, year [, is_dst]]]]]]]) | Integer | Returns UNIX timestamp for time/date. Default current date. |
| strftime(format [, timestamp]) | String | Formats a date/time as per current locale |
| strtotime(time [, now]) | Integer | Convert English datetime format to UNIX timestamp |
| time() | Integer | Returns current UNIX timestamp |
| Function | Returns | Does what |
|---|---|---|
| easter_date([year]) | Integer | Returns UNIX timestamp for midnight, Easter Day. Default current year |
| easter_days([year [, method]) | Integer | Returns no. of days from March 1 to Easter Day. Default current year |
| FrenchToJD(month, day, year) | Integer | Convert from the French Republican Calendar to a Julian Day Count |
| GregorianToJD(month, day, year) | Integer | Convert from the Gregorian Calendar to a Julian Day Count |
| JDDayOfWeek(juliandaycount [, mode]) | Mixed | Returns day of week in "mode" format |
| JDMonthName(juliandaycount [, mode]) | String | Returns month in "mode" format |
| JDToFrench(juliandaycount) | String | Converts Julian Day Count to date in French Republican Calendar |
| JDToGregorian(juliandaycount) | String | Converts Julian Day Count to date in the Gregorian Calendar |
| jdtojewish(juliandaycount [, hebrew [, fl]) | String | Converts Julian Day Count to date in the Jewish Calendar |
| JDToJulian(juliandaycount) | String | Converts Julian Day Count to date in the Julian Calendar |
| jdtounix(juliandaycount) | Integer | Converts Julian Day Count to UNIX timestamp |
| JewishToJD(month, day, year) | Integer | Convert from the Jewish Calendar to a Julian Day Count |
| JulianToJD(month, day, year) | Integer | Convert from the Julian Calendar to a Julian Day Count |
| unixtojd(timestamp) | Integer | Convert a UNIX timestamp to a Julian Day Count |
<?php
$test_string = "31-12-1999 12:34:56";
$test_timestamp = strtotime($test_string);
$timestamp_format = "d-m-Y H:i:s"; # European 24-hour format
# for AM/PM, use lower case "h" and append upper case "A", like this:
# $timestamp_format = "d-m-Y h:i:s A";
echo $test_timestamp." = ".date($timestamp_format, $test_timestamp)."\n";
?>