Timestamp functions

Spanner supports the following MySQL timestamp functions. You need to implement the MySQL functions in your Spanner database before you can use them. For more information on installing the functions, see Install MySQL functions .

Function list

Name	Summary
`mysql.DATEDIFF`	Subtracts two dates, returns the number of days between them.
`mysql.LOCALTIME`	Alias for `mysql.NOW` .
`mysql.LOCALTIMESTAMP`	Alias for `mysql.NOW` .
`mysql.NOW`	Returns the TIMESTAMP at which the query statement that contains this function started to run.

`mysql.DATEDIFF`

  mysql 
 . 
 DATEDIFF 
 ( 
 timestamp_expression1 
 , 
  
 timestamp_expression2 
 )

Description

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

This function supports the following arguments:

timestamp_expression1 : The first TIMESTAMP value (minuend).
timestamp_expression2 : The second TIMESTAMP value (subtrahend).

Return data type

INT64

Differences from MySQL

This function only accepts TIMESTAMP values. The MySQL version also accepts DATE or DATETIME values.

Example

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

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

`mysql.LOCALTIME`

  mysql 
 . 
 LOCALTIME 
 ()

Description

Returns the TIMESTAMP when the current query statement started to run. This function is an alias for mysql.NOW() and mysql.LOCALTIMESTAMP() .

This function doesn't support any arguments.

Return data type

TIMESTAMP

Example

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

  SELECT 
  
 mysql 
 . 
 LOCALTIME 
 () 
  
 as 
  
 current_query_time 
 ; 
 /* 
 +-------------------------------+ 
 | current_query_time            | 
 +-------------------------------+ 
 | 2025-06-03 12:28:32.123456+00 | 
 +-------------------------------+ 
 */

`mysql.LOCALTIMESTAMP`

  mysql 
 . 
 LOCALTIMESTAMP 
 ()

Description

Alias for NOW .

`mysql.NOW`

  mysql 
 . 
 NOW 
 ()

Description

Returns the TIMESTAMP at which the current query statement started to run. This function is an alias for mysql.LOCALTIME() and mysql.LOCALTIMESTAMP() .

This function doesn't support any arguments.

Return data type

TIMESTAMP

Example

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

  SELECT 
  
 mysql 
 . 
 NOW 
 () 
  
 as 
  
 current_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 query statement started to run. In this implementation, it behaves like mysql.NOW() .

This function doesn't support any arguments.

Return data type

TIMESTAMP

Differences from MySQL

While MySQL's UTC_TIMESTAMP() always returns a UTC timestamp regardless of the session 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:

  SELECT 
  
 mysql 
 . 
 UTC_TIMESTAMP 
 () 
  
 as 
  
 current_utc_ts 
 ; 
 /* 
 +-------------------------------+ 
 | current_utc_ts                | 
 +-------------------------------+ 
 | 2025-06-03 12:28:32.123456+00 | 
 +-------------------------------+ 
 */