MONTH_FLOOR

Description

Rounds down a datetime value to the nearest specified month interval. If a starting time (origin) is provided, it uses that time as the reference for calculating the interval.

Syntax

MONTH_FLOOR(<datetime>)
MONTH_FLOOR(<datetime>, <origin>)
MONTH_FLOOR(<datetime>, <period>)
MONTH_FLOOR(<datetime>, <period>, <origin>)

Parameters

Parameter	Description
<datetime>	The datetime value to round down, of type DATETIME or DATETIMEV2
<period>	The month interval value, of type INT, representing the number of months in each interval
<origin>	The starting point for the interval, of type DATETIME or DATETIMEV2; defaults to 0001-01-01 00:00:00

Return Value

Returns a value of type DATETIME, representing the rounded-down datetime value. The time portion of the result will be set to 00:00:00.

Example

SELECT MONTH_FLOOR("2023-07-13 22:28:18", 5);

+--------------------------------------------------------------+
| month_floor(cast('2023-07-13 22:28:18' as DATETIMEV2(0)), 5) |
+--------------------------------------------------------------+
| 2023-05-01 00:00:00                                          |
+--------------------------------------------------------------+

Note:

• If no period is specified, it defaults to a 1-month interval.
• The period must be a positive integer.
• The result is always rounded down to a past time.
• The time portion of the returned value is always set to 00:00:00.
• Unlike MONTH_CEIL, MONTH_FLOOR always discards the portion that exceeds the interval.

Best Practices

See also date_floor