php mysql php Mysql date and time function collection

A relatively complete collection of Mysql date and mysql time functions
DATE_FORMAT(date,format)
Format the date value according to the format string. The following modifiers can be used in the format string: %M month name (January...December)
%W week name (Sunday...Saturday)
%D day of the month with English prefix (1st, 2nd, 3rd, Etc. )
%Y Year, number, 4 digits
%y Year, number, 2 digits
%a Abbreviated name of the week (Sun...Sat)
%d Number of days in the month, number (00...31)
%e Number of days in the month, number (0...31)
%m Month, number (01...12)
%c Month, number (1...12)
%b Abbreviated month name (Jan... Dec)
%j Number of days in a year (001…366)
%H hours (00…23)
%k hours (0…23)
%h hours (01…12)
%I hours (01...12)
%l hours (1...12)
%i minutes, numbers (00...59)
%r time, 12 hours (hh:mm:ss [AP]M)
%T time , 24 hours (hh:mm:ss)
%S seconds (00...59)
%s seconds (00...59)
%p AM or PM
%w Number of days in a week (0=Sunday... 6=Saturday)
%U Week (0...52), where Sunday is the first day of the week
%u Week (0...52), where Monday is the first day of the week
%% A text "% ".
All other characters are copied to the result without interpretation.
mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%W %M %Y');
-> 'Saturday October 1997'
mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%H:%i:%s');
-> '22:23:00'
mysql> select DATE_FORMAT('1997-10-04 22:23:00',
'%D %y %a %d %m %b %j');
-> '4th 97 Sat 04 10 Oct 277'
mysql> select DATE_FORMAT('1997-10-04 22:23:00',
'%H %k %I %r %T %S %w');
-> '22 22 10 10:23:00 PM 22:23:00 00 6'
In MySQL3.23, in the format modification % is required before the character. In earlier versions of MySQL, % was optional.
TIME_FORMAT(time,format)
This is used like the DATE_FORMAT() function above, but the format string can only contain those format modifiers that handle hours, minutes, and seconds.
Other modifiers produce a NULL value or 0.
CURDATE()

CURRENT_DATE
Returns today's date value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.
mysql> select CURDATE();
-> '1997-12-15'
mysql> select CURDATE() + 0;
-> 19971215
CURTIME()

CURRENT_ TIME
With 'HH:MM:SS' or HHMMSS format returns the current time value, depending on whether the function is used in a string or numeric context.
mysql> select CURTIME();
-> '23:50:26'
mysql> select CURTIME() + 0;
-> 235026
NOW()

SYSDATE()
　
CURRENT_TIMESTAMP
With 'YYYY -MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format returns the current date and time, depending on whether the function is used in a string or numeric context.
mysql> select NOW();
-> '1997-12-15 23:50:26'
mysql> select NOW() + 0;
-> 19971215235026
UNIX_TIMESTAMP()
　
UNIX_TIMESTAMP(date)
If called without arguments, returns a Unix timestamp (number of seconds since '1970-01-01 00:00:00' GMT). If UNIX_TIMESTAMP() is called with a date parameter, it returns the number of seconds since '1970-01-01 00:00:00' GMT. date can be a DATE string, a DATETIME string, a TIMESTAMP, or a number in local time in YYMMDD or YYYYMMDD format.
mysql> select UNIX_TIMESTAMP();
-> 882226357
mysql> select UNIX_TIMESTAMP('1997-10-04 22:23:00');
-> 875996580
When UNIX_TIMESTAMP is used for a TIMESTAMP column, the function will Accepts values ​​directly, no implicit "string-to-unix-timestamp" transformation http://www.knowsky.com/.
FROM_UNIXTIME(unix_timestamp)
Returns the value represented by the unix_timestamp parameter in the format of 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS, depending on whether the function is used in a string or numeric context.
mysql> select FROM_UNIXTIME(875996580);
-> '1997-10-04 22:23:00'
mysql> select FROM_UNIXTIME(875996580) + 0;
-> 1 9971004222300
FROM_UNIXTIME(unix_timestamp,format)
Return A string representing a Unix timestamp, formatted according to the format string. format can contain the same modifiers as the entries listed by the DATE_FORMAT() function.
mysql> select FROM_UNIXTIME(UNIX_TIMESTAMP(),
'%Y %D %M %h:%i:%s %x');
-> '1997 23rd December 03:43:30 x'
SEC_TO_TIME(seconds )
Returns the seconds parameter, converted to hours, minutes and seconds. The value is formatted in 'HH:MM:SS' or HHMMSS, depending on whether the function is used in a string or numeric context.
mysql> select SEC_TO_TIME(2378);
-> '00:39:38'
mysql> select SEC_TO_TIME(2378) + 0;
-> 3938
TIME_TO_SEC(time)
Return the time parameter, converted into seconds.
mysql> select TIME_TO_SEC('22:23:00');
-> 80580
mysql> select TIME_TO_SEC('00:39:38');
-> 2378

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