MySQL Date time function

DayOfWeek (date)
Return date is the day of the week (1= Sunday, 2 = Monday,...... 7= Saturday, ODBC Standard)
Mysql> Select DayOfWeek (' 1998-02-03 ');
-> 3
Weekday (date)
Return date is the day of the week (0= Monday, 1 = Tuesday,...... 6= Sunday).
Mysql> Select Weekday (' 1997-10-04 22:23:00 ');
-> 5
Mysql> Select Weekday (' 1997-11-05 ');
-> 2
DayOfMonth (date)
Returns date is the day ordinal of January (within 1 to 31)
Mysql> Select DayOfMonth (' 1998-02-03 ');
-> 3
DayOfYear (date)
Return date is the day ordinal of the year (within 1 to 366)
Mysql> Select DayOfYear (' 1998-02-03 ');
-> 34
MONTH (date)
Returns the number of months in date
Mysql> Select MONTH (' 1998-02-03 ');
-> 2
Dayname (date)
Return date is the day of the week (returned by English name)
Mysql> Select Dayname ("1998-02-05");
-> ' Thursday '
MonthName (date)
Return date is a few months (returned by English name)
Mysql> Select MonthName ("1998-02-05");
-> ' February '
Quarter (date)
Return date is the quarter ordinal of a year
Mysql> Select quarter (' 98-04-01 ');
-> 2
WEEK (Date,first)
Returns date is the week ordinal of a year (first default 0,first value 1 means Monday is the beginning of the week, 0 starts in Sunday)
Mysql> Select WEEK (' 1998-02-20 ');
-> 7
Mysql> Select WEEK (' 1998-02-20 ', 0);
-> 7
Mysql> Select WEEK (' 1998-02-20 ', 1);
-> 8
Year (date)
Returns the year of date (range from 1000 to 9999)
Mysql> Select year (' 98-02-03 ');
-> 1998
HOUR (Time)
The number of hours to return time (range 0 to 23)
Mysql> Select HOUR (' 10:05:03 ');
-> 10
MINUTE (Time)
Returns the number of minutes in time (range 0 to 59)
Mysql> Select MINUTE (' 98-02-03 10:05:03 ');
-> 5
SECOND (Time)
Returns the number of seconds in time (range is 0 to 59)
Mysql> Select SECOND (' 10:05:03 ');
-> 3
Period_add (P,n)
Increase n months to time P and return (P's format yymm or YYYYMM)
Mysql> Select Period_add (9801,2);
-> 199803
Period_diff (P1,P2)
Returns the number of months between periods P1 and P2 (P1 and P2 formats yymm or YYYYMM)
Mysql> Select Period_diff (9802,199703);

-> 11

Date_add (Date,interval expr type)
Date_sub (Date,interval expr type)
Adddate (Date,interval expr type)
Subdate (Date,interval expr type)
Add and subtract a date time
(Adddate () and subdate () are synonyms for Date_add () and Date_sub (), and you can also use operators and-instead of functions