LAST_DAY

Description

Returns the last day of the month that the input date falls in. Depending on the month, the last day is:

• 28th: February in a common (non‑leap) year
• 29th: February in a leap year
• 30th: April, June, September, November
• 31st: January, March, May, July, August, October, December

This function behaves the same as MySQL’s LAST_DAY function.

Syntax

LAST_DAY(`<date_or_time_expr>`)

Arguments

Parameter	Description
<date_or_time_expr>	A valid date expression. Supports DATE/DATETIME types. For exact formats, see datetime conversion and date conversion.

Return value

Returns a value of type DATE, representing the last day of the month of the input date (format YYYY-MM-DD).

• If the input is NULL, returns NULL.

Examples

-- Input is DATE; returns the last day of February in a leap year
mysql> SELECT LAST_DAY('2000-02-03');
+------------------------+
| LAST_DAY('2000-02-03') |
+------------------------+
| 2000-02-29             |
+------------------------+

-- Input is DATETIME; time part is ignored
mysql> SELECT LAST_DAY('2023-04-15 12:34:56');
+---------------------------------+
| LAST_DAY('2023-04-15 12:34:56') |
+---------------------------------+
| 2023-04-30                      |
+---------------------------------+

-- February in a common (non‑leap) year
mysql> SELECT LAST_DAY('2021-02-01');
+------------------------+
| LAST_DAY('2021-02-01') |
+------------------------+
| 2021-02-28             |
+------------------------+

-- Example of a 31‑day month
mysql> SELECT LAST_DAY('2023-01-10');
+------------------------+
| LAST_DAY('2023-01-10') |
+------------------------+
| 2023-01-31             |
+------------------------+

-- Input is NULL; returns NULL
mysql> SELECT LAST_DAY(NULL);
+----------------+
| LAST_DAY(NULL) |
+----------------