Date Functions

3.1

Date Functions

Current Date/Time Functions

There are a number of functions that give the current date and time. The DATE() function is a date formatting function, but I include it in the list because it is often confused with the NOW() function
CURRENT_DATE, CURRENT_TIME, UTC_DATE, UTC_TIME can be used with the parentheses “()” or not. They accept no parameters

Table 1. Current Date Functions

Function	Type	Example	Result
NOW() * Returns current local date and time.	date/time	NOW()	ex. ‘2020-02-24 09:31:31’
DATE(date) * extracts the date from input. If time is included, the time is dropped.	date/time	DATE('2020-01-01 11:31:31')	‘2020-02-24’
CURRENT_DATE() * Returns current local date	date	CURRENT_DATE	‘2020-02-24’
CURRENT_TIME() * Returns current local time.	time	CURRENT_TIME	‘11:52:10’
UTC_DATE() * Returns current UTC date.	date	UTC_DATE	‘2020-02-24’
UTC_TIME() * Returns current UTC date.	time	UTC_TIME	‘18:52:10’

SELECT NOW() AS 'NOW()', DATE('2020-01-01') AS 'DATE(), date only', CURRENT_DATE AS 'CURRENT_DATE', CURRENT_TIME AS 'CURRENT_TIME', UTC_DATE AS 'UTC_DATE', UTC_TIME AS 'UTC_TIME';

Results:

DATE_ADD

• Returns a date with a DATE or DATETIME value equal to the original value plus the specified interval.

Table 2. DATE_ADD Function

Function	Type	Example	Result
DATE_ADD(date, interval expression unit)	DATE, DATETIME	DATE_ADD(‘2020-01-01’, INTERVAL 1 DAY)	‘202-01-02’

Code Snippet:

USE bike; SELECT order_date, DATE_ADD(order_date, INTERVAL 1 DAY) AS 'ORDER DATE PLUS 1 day', DATE_ADD(order_date, INTERVAL 6 MONTH) AS 'ORDER DATE PLUS 6 months', DATE_ADD(order_date, INTERVAL '2 12' DAY_HOUR) AS 'ORDER DATE PLUS 2 days 1 hour' FROM cust_order;

Results:

DATE_FORMAT

• Dates must be enclosed in quotes • You can pass a DATE or DATETIME datatype to DATE_FORMAT

Table 3. DATE_FORMAT Function

Function	Type	Example	Result
DATE_FORMAT	DATE	DATE_FORMAT(‘2020-09-03’, ‘%m/%d/%y’)	09/03/14

Code Snippet:

USE world; SELECT name, continent, DATE_FORMAT('2020-01-28', '%m/%d/%y') FROM country;

Results:

Table 4. Format List

Specifier	Description
%a	Abbreviated weekday name (Sun..Sat)
%b	Abbreviated month name (Jan..Dec)
%c	Month, numeric (0..12)
%D	Day of the month with English suffix (0th, 1st, 2nd, 3rd, …)
%d	Day of the month, numeric (00..31)
%e	Day of the month, numeric (0..31)
%f	Microseconds (000000..999999)
%H	Hour (00..23)
%h	Hour (01..12)
%I	Hour (01..12)
%i	Minutes, numeric (00..59)
%j	Day of year (001..366)
%k	Hour (0..23)
%l	Hour (1..12)
%M	Month name (January..December)
%m	Month, numeric (00..12)
%p	AM or PM
%r	Time, 12-hour (*hh:mm:ss* followed by AM or PM)
%S	Seconds (00..59)
%s	Seconds (00..59)
%T	Time, 24-hour (*hh:mm:ss*)
%U	Week (00..53), where Sunday is the first day of the week; WEEK() mode 0
%u	Week (00..53), where Monday is the first day of the week; WEEK() mode 1
%V	Week (01..53), where Sunday is the first day of the week; WEEK() mode 2; used with %X
%v	Week (01..53), where Monday is the first day of the week; WEEK() mode 3; used with %x
%W	Weekday name (Sunday..Saturday)
%w	Day of the week (0=Sunday..6=Saturday)
%X	Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x	Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
%Y	Year, numeric, four digits
%y	Year, numeric (two digits)
%%	A literal % character
%x	x, for any “x” not listed above

DATEDIFF

The DATEDIFF function has two parameters. Both are dates.
The value returned by the function is an integer and is the number of days between the two dates.
If you provide the latest date, first the results will be positive. Otherwise, it will be negative.

Example:

SELECT DATEDIFF('2018-01-01', '2019-01-01') AS 'Date Difference';

Results:

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