INTERVAL function

Returns the time interval between two DATE, DATETIME, or DATETIME-TZ values as an INT64 value.

Syntax 

 

INTERVAL ( datetime1 , datetime2 , interval-unit )

datetime1

An expression whose value is a DATE, DATETIME, or DATETIME-TZ.

datetime2

An expression whose value is a DATE, DATETIME, or DATETIME-TZ.

interval-unit

A character constant, or a character expression that evaluates to one of the following time units: ‘years’, ‘months’, ‘weeks’, ‘days’, 'hours’, ‘minutes’, ‘seconds’ or ‘milliseconds’. These values are case insensitive and might be singular.

Notes 

This function returns a signed integer value (positive or negative). For example, if datetime1 is less than datetime2, the INTERVAL function returns a negative value.

If datetime1 or datetime2 is a DATE or DATETIME, the time value defaults to midnight and the time zone value defaults to the session's time zone, respectively.

You are responsible for managing value overflow, if any.

See also 

– Date subtraction operator, – Datetime subtraction operator, ADD-INTERVAL function, DATE function, DATETIME function, DATETIME-TZ function