Categories:

Date & time functions

YEAR* / DAY* / WEEK* / MONTH / QUARTER¶

Extracts the corresponding date part from a date or timestamp.

These functions are alternatives to using the DATE_PART (or EXTRACT) function with the equivalent date part (see Supported date and time parts).

See also:

HOUR / MINUTE / SECOND

Syntax¶

YEAR( <date_or_timestamp_expr> )

YEAROFWEEK( <date_or_timestamp_expr> )
YEAROFWEEKISO( <date_or_timestamp_expr> )

DAY( <date_or_timestamp_expr> )

DAYOFMONTH( <date_or_timestamp_expr> )
DAYOFWEEK( <date_or_timestamp_expr> )
DAYOFWEEKISO( <date_or_timestamp_expr> )
DAYOFYEAR( <date_or_timestamp_expr> )

WEEK( <date_or_timestamp_expr> )

WEEKOFYEAR( <date_or_timestamp_expr> )
WEEKISO( <date_or_timestamp_expr> )

MONTH( <date_or_timestamp_expr> )

QUARTER( <date_or_timestamp_expr> )
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Arguments¶

date_or_timestamp_expr

An expression of type DATE or TIMESTAMP.

Returns¶

This function returns a value of type NUMBER.

Usage notes¶

Function name

Date part extracted from input date or timestamp

Possible values

YEAR

Year

Any valid year (for example, 2025)

YEAROFWEEK [1]

Year that the extracted week belongs to

Any valid year (for example, 2025)

YEAROFWEEKISO

Year that the extracted week belongs to using ISO semantics

Any valid year (for example, 2025)

DAY , DAYOFMONTH

Day (number) of the month

1 to 31

DAYOFWEEK [1]

Day (number) of the week

0 to 7

DAYOFWEEKISO

Day (number) of the week using ISO semantics

1 to 7

DAYOFYEAR

Day (number) of the year

1 to 366

WEEK , WEEKOFYEAR [1]

Week (number) of the year

1 to 54

WEEKISO

Week (number) of the year using ISO semantics

1 to 53

MONTH

Month (number) of the year

1 to 12

QUARTER

Quarter (number) of the year

1 to 4

[1] Results dictated by the values set for the WEEK_OF_YEAR_POLICY and/or WEEK_START session parameters.

For details about ISO semantics and the parameter, see Calendar weeks and weekdays.

Examples¶

The following example demonstrates the use of the functions YEAR, QUARTER, MONTH, DAY, DAYOFWEEK, and DAYOFYEAR:

SELECT '2025-04-11T23:39:20.123-07:00'::TIMESTAMP AS tstamp,
       YEAR(tstamp) AS "YEAR",
       QUARTER(tstamp) AS "QUARTER OF YEAR",
       MONTH(tstamp) AS "MONTH",
       DAY(tstamp) AS "DAY",
       DAYOFMONTH(tstamp) AS "DAY OF MONTH",
       DAYOFYEAR(tstamp) AS "DAY OF YEAR";
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+-------------------------+------+-----------------+-------+-----+--------------+-------------+
| TSTAMP                  | YEAR | QUARTER OF YEAR | MONTH | DAY | DAY OF MONTH | DAY OF YEAR |
|-------------------------+------+-----------------+-------+-----+--------------+-------------|
| 2025-04-11 23:39:20.123 | 2025 |               2 |     4 |  11 |           11 |         101 |
+-------------------------+------+-----------------+-------+-----+--------------+-------------+

The following example demonstrates the use of the functions WEEK, WEEKISO, WEEKOFYEAR, YEAROFWEEK, and YEAROFWEEKISO. The session parameter WEEK_OF_YEAR_POLICY is set to 1, so that the first week of the year is the week that contains January 1st of that year.

ALTER SESSION SET WEEK_OF_YEAR_POLICY = 1;
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SELECT '2016-01-02T23:39:20.123-07:00'::TIMESTAMP AS tstamp,
       WEEK(tstamp) AS "WEEK",
       WEEKISO(tstamp) AS "WEEK ISO",
       WEEKOFYEAR(tstamp) AS "WEEK OF YEAR",
       YEAROFWEEK(tstamp) AS "YEAR OF WEEK",
       YEAROFWEEKISO(tstamp) AS "YEAR OF WEEK ISO";
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+-------------------------+------+----------+--------------+--------------+------------------+
| TSTAMP                  | WEEK | WEEK ISO | WEEK OF YEAR | YEAR OF WEEK | YEAR OF WEEK ISO |
|-------------------------+------+----------+--------------+--------------+------------------|
| 2016-01-02 23:39:20.123 |    1 |       53 |            1 |         2016 |             2015 |
+-------------------------+------+----------+--------------+--------------+------------------+

The following example also demonstrates the use of the functions WEEK, WEEKISO, WEEKOFYEAR, YEAROFWEEK, and YEAROFWEEKISO. The session parameter WEEK_OF_YEAR_POLICY is set to indicate that the first week of the year is the first week of the year that contains at least four days from that year. In this example, the week December 27, 2015 through January 2, 2016 is considered the last week of 2015, not the first week of 2016. Even though the week contains Friday January 1, 2016, less than half of the week is in 2016.

ALTER SESSION SET WEEK_OF_YEAR_POLICY = 0;
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SELECT '2016-01-02T23:39:20.123-07:00'::TIMESTAMP AS tstamp,
       WEEK(tstamp) AS "WEEK",
       WEEKISO(tstamp) AS "WEEK ISO",
       WEEKOFYEAR(tstamp) AS "WEEK OF YEAR",
       YEAROFWEEK(tstamp) AS "YEAR OF WEEK",
       YEAROFWEEKISO(tstamp) AS "YEAR OF WEEK ISO";
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+-------------------------+------+----------+--------------+--------------+------------------+
| TSTAMP                  | WEEK | WEEK ISO | WEEK OF YEAR | YEAR OF WEEK | YEAR OF WEEK ISO |
|-------------------------+------+----------+--------------+--------------+------------------|
| 2016-01-02 23:39:20.123 |   53 |       53 |           53 |         2015 |             2015 |
+-------------------------+------+----------+--------------+--------------+------------------+

The following example demonstrates the use of the functions DAYOFWEEK and DAYOFWEEKISO. The session parameter WEEK_START is set to indicate that the week starts on Sunday.

ALTER SESSION SET WEEK_START = 7;
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The timestamp in the following query is for April 5, 2025, which was a Saturday. The DAYOFWEEK function returns 7 for Saturday, because the first day of the week is set to Sunday. The DAYOFWEEKISO function returns 6 because the first day of the week using ISO semantics is Monday. For more information about ISO semantics and the WEEK_START parameter, see Calendar weeks and weekdays.

SELECT '2025-04-05T23:39:20.123-07:00'::TIMESTAMP AS tstamp,
       DAYOFWEEK(tstamp) AS "DAY OF WEEK",
       DAYOFWEEKISO(tstamp) AS "DAY OF WEEK ISO";
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+-------------------------+-------------+-----------------+
| TSTAMP                  | DAY OF WEEK | DAY OF WEEK ISO |
|-------------------------+-------------+-----------------|
| 2025-04-05 23:39:20.123 |           7 |               6 |
+-------------------------+-------------+-----------------+

The following example also demonstrates the use of the functions DAYOFWEEK and DAYOFWEEKISO. The session parameter WEEK_START is set to indicate that the week starts on Monday.

ALTER SESSION SET WEEK_START = 1;
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SELECT '2025-04-05T23:39:20.123-07:00'::TIMESTAMP AS tstamp,
       DAYOFWEEK(tstamp) AS "DAY OF WEEK",
       DAYOFWEEKISO(tstamp) AS "DAY OF WEEK ISO";
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+-------------------------+-------------+-----------------+
| TSTAMP                  | DAY OF WEEK | DAY OF WEEK ISO |
|-------------------------+-------------+-----------------|
| 2025-04-05 23:39:20.123 |           6 |               6 |
+-------------------------+-------------+-----------------+

For more examples, see Working with date and time values.

For more detailed examples of the week-related functions (DAYOFWEEK, WEEK, WEEKOFYEAR, YEAROFWEEK, and so on), see Calendar weeks and weekdays.

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