Spanner supports the following MySQL timestamp functions.You need to implement the MySQL functions in yourSpanner database before you can use them. For more information oninstalling the functions, seeInstall MySQL functions.

Function list

mysql.DATEDIFF

mysql.DATEDIFF(timestamp_expression1,timestamp_expression2)

Description

Calculates the number of days between twoTIMESTAMP values(timestamp_expression1 -timestamp_expression2).

This function supports the following arguments:

• timestamp_expression1: The firstTIMESTAMP value (minuend).
• timestamp_expression2: The secondTIMESTAMP value (subtrahend).

Return data type

INT64

Differences from MySQL

This function only acceptsTIMESTAMP values. The MySQL version also acceptsDATE orDATETIME values.

Example

The following example calculates the difference in days between two timestamps:

SELECTmysql.DATEDIFF(TIMESTAMP'2025-01-10 10:00:00',TIMESTAMP'2025-01-01 05:00:00')asdays_difference;/*+-----------------+| days_difference |+-----------------+| 9               |+-----------------+*/

mysql.LOCALTIME

mysql.LOCALTIME()

Description

Returns theTIMESTAMP when the current query statement started to run. Thisfunction is an alias formysql.NOW() andmysql.LOCALTIMESTAMP().

This function doesn't support any arguments.

Return data type

TIMESTAMP

Example

The following example returns the start time of the current query:

SELECTmysql.LOCALTIME()ascurrent_query_time;/*+-------------------------------+| current_query_time            |+-------------------------------+| 2025-06-03 12:28:32.123456+00 |+-------------------------------+*/

mysql.LOCALTIMESTAMP

mysql.LOCALTIMESTAMP()

Description

Alias forNOW.

mysql.NOW

mysql.NOW()

Description

Returns theTIMESTAMP at which the current query statement started to run. Thisfunction is an alias formysql.LOCALTIME() andmysql.LOCALTIMESTAMP().

This function doesn't support any arguments.

Return data type

TIMESTAMP

Example

The following example returns the start time of the current query:

SELECTmysql.NOW()ascurrent_query_time;/*+-------------------------------+| current_query_time            |+-------------------------------+| 2025-06-03 12:28:32.123456+00 |+-------------------------------+*/

mysql.UTC_TIMESTAMP

mysql.UTC_TIMESTAMP()

Description

Returns the current Coordinated Universal Time (UTC)TIMESTAMP at which the querystatement started to run. In this implementation, it behaves likemysql.NOW().

This function doesn't support any arguments.

Return data type

TIMESTAMP

Differences from MySQL

While MySQL'sUTC_TIMESTAMP() always returns a UTC timestamp regardless of thesession timezone, this function, as implemented, returns the query start time,which is inherently UTC in GoogleSQL.

Example

The following example returns the current UTC timestamp at the start of the query:

SELECTmysql.UTC_TIMESTAMP()ascurrent_utc_ts;/*+-------------------------------+| current_utc_ts                |+-------------------------------+| 2025-06-03 12:28:32.123456+00 |+-------------------------------+*/