DATE_TRUNC function - Amazon Redshift
SyntaxArgumentsReturn typeExamples

DATE_TRUNC function

The DATE_TRUNC function truncates a timestamp expression or literal based on the date part that you specify, such as hour, day, or month.

Syntax

DATE_TRUNC('datepart', timestamp)

Arguments

datepart

The date part to which to truncate the timestamp value. The input timestamp is truncated to the precision of the input datepart. For example, month truncates to the first day of the month. Valid formats are as follows:

  • microsecond, microseconds

  • millisecond, milliseconds

  • second, seconds

  • minute, minutes

  • hour, hours

  • day, days

  • week, weeks

  • month, months

  • quarter, quarters

  • year, years

  • decade, decades

  • century, centuries

  • millennium, millennia

For more information about abbreviations of some formats, see Date parts for date or timestamp functions

timestamp

A timestamp column or an expression that implicitly converts to a timestamp.

Return type

TIMESTAMP

Examples

Truncate the input timestamp to the second.

SELECT DATE_TRUNC('second', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-30 04:05:06

Truncate the input timestamp to the minute.

SELECT DATE_TRUNC('minute', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-30 04:05:00

Truncate the input timestamp to the hour.

SELECT DATE_TRUNC('hour', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-30 04:00:00

Truncate the input timestamp to the day.

SELECT DATE_TRUNC('day', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-30 00:00:00

Truncate the input timestamp to the first day of a month.

SELECT DATE_TRUNC('month', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-01 00:00:00

Truncate the input timestamp to the first day of a quarter.

SELECT DATE_TRUNC('quarter', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-04-01 00:00:00

Truncate the input timestamp to the first day of a year.

SELECT DATE_TRUNC('year', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2020-01-01 00:00:00

Truncate the input timestamp to the first day of a century.

SELECT DATE_TRUNC('millennium', TIMESTAMP '20200430 04:05:06.789');
date_trunc
2001-01-01 00:00:00

Truncate the input timestamp to the Monday of a week.

select date_trunc('week', TIMESTAMP '20220430 04:05:06.789');
date_trunc
2022-04-25 00:00:00

In the following example, the DATE_TRUNC function uses the 'week' date part to return the date for the Monday of each week. 

select date_trunc('week', saletime), sum(pricepaid) from sales where
saletime like '2008-09%' group by date_trunc('week', saletime) order by 1;

date_trunc  |    sum
------------+-------------
2008-09-01  | 2474899
2008-09-08  | 2412354
2008-09-15  | 2364707
2008-09-22  | 2359351
2008-09-29  |  705249