MySQL TO_DAYS() Function

The TO_DAYS() function in MySQL calculates the number of days between a specified date and the hypothetical date "0000-00-00" (year 0). This is useful for date-based calculations or when you need to represent dates as a numerical value.

TO_DAYS(): Definition and Usage

TO_DAYS() converts a date into a day number. This number represents the number of days that have elapsed since the beginning of the Julian calendar (year 0). The output is an integer. It's important to note that TO_DAYS() only works reliably with dates within the Gregorian calendar system.

Syntax


TO_DAYS(date)

Parameter Values

Parameter	Description
`date`	The date value. This is required.

Related Function

The FROM_DAYS() function performs the reverse operation, converting a day number back into a date.

Examples

Calculating Days Since Year 0

This example calculates the number of days between June 20th, 2017 and year 0.

Syntax


SELECT TO_DAYS("2017-06-20");

Output

Calculating Days Since Year 0 from a DATETIME Value

This demonstrates using TO_DAYS() with a datetime value. The time component is ignored; only the date part is used.

Syntax


SELECT TO_DAYS("2017-06-20 09:34:00");