Interval functions

GoogleSQL for BigQuery supports the following interval functions.

Function list

Name	Summary
EXTRACT	Extracts part of an INTERVAL value.
JUSTIFY_DAYS	Normalizes the day part of an INTERVAL value.
JUSTIFY_HOURS	Normalizes the time part of an INTERVAL value.
JUSTIFY_INTERVAL	Normalizes the day and time parts of an INTERVAL value.
MAKE_INTERVAL	Constructs an INTERVAL value.

EXTRACT

EXTRACT(part FROM interval_expression)

Description

Returns the value corresponding to the specified date part. The part must be one of YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, MILLISECOND or MICROSECOND.

Return Data Type

INTERVAL

Examples

In the following example, different parts of two intervals are extracted.

SELECT
  EXTRACT(YEAR FROM i) AS year,
  EXTRACT(MONTH FROM i) AS month,
  EXTRACT(DAY FROM i) AS day,
  EXTRACT(HOUR FROM i) AS hour,
  EXTRACT(MINUTE FROM i) AS minute,
  EXTRACT(SECOND FROM i) AS second,
  EXTRACT(MILLISECOND FROM i) AS milli,
  EXTRACT(MICROSECOND FROM i) AS micro
FROM
  UNNEST([INTERVAL '1-2 3 4:5:6.789999' YEAR TO SECOND,
          INTERVAL '0-13 370 48:61:61' YEAR TO SECOND]) AS i

/*------+-------+-----+------+--------+--------+-------+--------*
 | year | month | day | hour | minute | second | milli | micro  |
 +------+-------+-----+------+--------+--------+-------+--------+
 | 1    | 2     | 3   | 4    | 5      | 6      | 789   | 789999 |
 | 1    | 1     | 370 | 49   | 2      | 1      | 0     | 0      |
 *------+-------+-----+------+--------+--------+-------+--------*/

When a negative sign precedes the time part in an interval, the negative sign distributes over the hours, minutes, and seconds. For example:

SELECT
  EXTRACT(HOUR FROM i) AS hour,
  EXTRACT(MINUTE FROM i) AS minute
FROM
  UNNEST([INTERVAL '10 -12:30' DAY TO MINUTE]) AS i

/*------+--------*
 | hour | minute |
 +------+--------+
 | -12  | -30    |
 *------+--------*/

When a negative sign precedes the year and month part in an interval, the negative sign distributes over the years and months. For example:

SELECT
  EXTRACT(YEAR FROM i) AS year,
  EXTRACT(MONTH FROM i) AS month
FROM
  UNNEST([INTERVAL '-22-6 10 -12:30' YEAR TO MINUTE]) AS i

/*------+--------*
 | year | month  |
 +------+--------+
 | -22  | -6     |
 *------+--------*/

JUSTIFY_DAYS

JUSTIFY_DAYS(interval_expression)

Description

Normalizes the day part of the interval to the range from -29 to 29 by incrementing/decrementing the month or year part of the interval.

Return Data Type

INTERVAL

Example

SELECT
  JUSTIFY_DAYS(INTERVAL 29 DAY) AS i1,
  JUSTIFY_DAYS(INTERVAL -30 DAY) AS i2,
  JUSTIFY_DAYS(INTERVAL 31 DAY) AS i3,
  JUSTIFY_DAYS(INTERVAL -65 DAY) AS i4,
  JUSTIFY_DAYS(INTERVAL 370 DAY) AS i5

/*--------------+--------------+-------------+---------------+--------------*
 | i1           | i2           | i3          | i4            | i5           |
 +--------------+--------------+-------------+---------------+--------------+
 | 0-0 29 0:0:0 | -0-1 0 0:0:0 | 0-1 1 0:0:0 | -0-2 -5 0:0:0 | 1-0 10 0:0:0 |
 *--------------+--------------+-------------+---------------+--------------*/

JUSTIFY_HOURS

JUSTIFY_HOURS(interval_expression)

Description

Normalizes the time part of the interval to the range from -23:59:59.999999 to 23:59:59.999999 by incrementing/decrementing the day part of the interval.

Return Data Type

INTERVAL

Example

SELECT
  JUSTIFY_HOURS(INTERVAL 23 HOUR) AS i1,
  JUSTIFY_HOURS(INTERVAL -24 HOUR) AS i2,
  JUSTIFY_HOURS(INTERVAL 47 HOUR) AS i3,
  JUSTIFY_HOURS(INTERVAL -12345 MINUTE) AS i4

/*--------------+--------------+--------------+-----------------*
 | i1           | i2           | i3           | i4              |
 +--------------+--------------+--------------+-----------------+
 | 0-0 0 23:0:0 | 0-0 -1 0:0:0 | 0-0 1 23:0:0 | 0-0 -8 -13:45:0 |
 *--------------+--------------+--------------+-----------------*/

JUSTIFY_INTERVAL

JUSTIFY_INTERVAL(interval_expression)

Description

Normalizes the days and time parts of the interval.

Return Data Type

INTERVAL

Example

SELECT JUSTIFY_INTERVAL(INTERVAL '29 49:00:00' DAY TO SECOND) AS i

/*-------------*
 | i           |
 +-------------+
 | 0-1 1 1:0:0 |
 *-------------*/

MAKE_INTERVAL

MAKE_INTERVAL([year][, month][, day][, hour][, minute][, second])

Description

Constructs an INTERVAL object using INT64 values representing the year, month, day, hour, minute, and second. All arguments are optional, 0 by default, and can be named arguments.

Return Data Type

INTERVAL

Example

SELECT
  MAKE_INTERVAL(1, 6, 15) AS i1,
  MAKE_INTERVAL(hour => 10, second => 20) AS i2,
  MAKE_INTERVAL(1, minute => 5, day => 2) AS i3

/*--------------+---------------+-------------*
 | i1           | i2            | i3          |
 +--------------+---------------+-------------+
 | 1-6 15 0:0:0 | 0-0 0 10:0:20 | 1-0 2 0:5:0 |
 *--------------+---------------+-------------*/