Reference : Date Formats

PHP

Component -> UNIX timestamp (seconds)

int mktime ( [int hour [, int minute [, int second [, int month [, int day [, int year [, int is_dst]]]]]]] )

UNIX timestamp (seconds) -> Component

array getdate ( [int timestamp] )

UNIX timestamp (seconds) -> Formatted string

string date ( string format [, int timestamp] )

Javascript

Date object constructors

Date()                                          //Use the current date and time
Date(dateString)                                //String format is "month day, year hours:minutes:seconds".
Date(year, month, day)                          //Year is 0 to 99, Month is 0 to 11, Day is 1 to 31
Date(year, month, day, hours, minutes, seconds)

Date object -> components

d.getHours();    //0-23
d.getMinutes();  //0-59
d.getSeconds();  //0-59
d.getMonth();    //0-11
d.getDate();     //1-31
d.getDay();      //0-6
d.getYear();     //Years since 1900
d.getFullYear(); //YYYY
d.getTime();     //ms since epoch

Date object -> UNIX timestamp (milliseconds)

d.getTime();

UNIX timestamp (milliseconds) -> Date object

pre. var d = new Date();
d.setTime(...);

MySQL

See also MySQL Manual - Date-Time functions

Passing dates to MySQL

INSERT INTO datetable (adate) VALUES ('2006-06-06');
INSERT INTO timetable (atime) VALUES ('21:55:01');
INSERT INTO bothtable (atdat) VALUES ('2006-06-06 21:55:01');

Data Types

• DATE ''YYYY-MM-DD ('1000-01-01' to '9999-12-31')''. Can be assigned as string or number.
• TIME ''HH:MM:SS ('838:59:59' to '838:59:59')''. Can be assigned as string or number.
• DATETIME ''YYYY-MM-DD HH:MM:SS ('1000-01-01 00:00:00' to '9999-12-31 23:59:59')''. Can be assigned as string or number.
• TIMESTAMP ''YYYY-MM-DD HH:MM:SS ('1970-01-01 00:00:00' to '2037-something')''. +0 to get as number

Functions

• ''CURDATE()'' returns 'YYYY-MM-DD' or YYYYMMDD.
• ''CURTIME()'' returns 'HH:MM:SS' or HHMMSS.
• ''DATE(expr)'' returns the DATE part of expr.
• ''DAY(date)'', ''DAYOFMONTH(date)'' 0..31
• ''DAYNAME(date)''
• ''DAYOFWEEK(date)'' 1(Sunday)..7(Saturday)
• ''FROM_UNIXTIME(timestamp)'', ''FROM_UNIXTIME(timestamp, fmt)'' timestamp is seconds since epoch
• ''DATE_FORMAT(date,fmt)''

Ranges for the month and day specifiers begin with zero due to the fact that MySQL allows the storing of incomplete dates such as '2004-00-00'.