> This page location: Date Functions > DATE_PART > Full Neon documentation index: https://neon.com/docs/llms.txt # PostgreSQL DATE_PART() Function **Info:** The `DATE_PART()` function works the same across any PostgreSQL deployment, so the examples here apply wherever you run Postgres. If you're an enterprise looking for managed cloud Postgres built for the AI era, [Lakebase](https://www.databricks.com/product/lakebase) delivers high performance, strong security, and native integration with the Lakehouse. If you're a developer or startup who needs to ship and scale fast, [Neon](https://neon.com) is the Postgres platform built for you. **Summary**: in this tutorial, you will learn how to use the PostgreSQL `DATE_PART()` function to retrieve the subfields such as year, month, and week from a [date](../postgresql-tutorial/postgresql-date) or [time](../postgresql-tutorial/postgresql-time) value. ## Introduction to the PostgreSQL DATE_PART() function The `DATE_PART()` function allows you to extract a subfield from a date or time value. The following illustrates the basic syntax for the `DATE_PART()` function: ```sql DATE_PART(field, source) ``` The `DATE_PART()` function has two optional parameters `field` and `source`. The `field` is an identifier that determines what to extract from the `source`. The values of the field must be one of the following permitted values: - century - decade - year - month - day - hour - minute - second - microseconds - milliseconds - dow - doy - epoch - isodow - isoyear - timezone - timezone_hour - timezone_minute The `source` is a temporal expression that evaluates to [`TIMESTAMP`](../postgresql-tutorial/postgresql-timestamp), [`TIME`](../postgresql-tutorial/postgresql-time), or [`INTERVAL`](../postgresql-tutorial/postgresql-interval). If the `source` evaluates to `DATE`, the function will be cast to `TIMESTAMP`. The `DATE_PART()` function returns a value whose type is double precision. ## PostgreSQL DATE_PART() function examples Let's explore some examples of using the `DATE_PART()` function. ### 1) Basic PostgreSQL DATE_PART() function example The following example uses the `DATE_PART()` function to extract the century from a timestamp: ```sql SELECT date_part('century',TIMESTAMP '2017-01-01'); ``` Output: ```text date_part ----------- 21 (1 row) ``` ### 2) Extracting the year from a timestamp To extract the year from the same timestamp, you pass the year to the `field` argument: ```sql SELECT date_part('year',TIMESTAMP '2017-01-01'); ``` Output: ```text date_part ----------- 2017 (1 row) ``` ### 3) Extracting the quarter from a timestamp The following example uses the `DATE_PART()` function to extract the quarter from a timestamp: ```sql SELECT date_part('quarter',TIMESTAMP '2017-01-01'); ``` Output: ```text date_part ----------- 1 (1 row) ``` ### 4) Extracting month from a timestamp The following example uses the `DATE_PART()` function to extract the month from a timestamp: ```sql SELECT date_part('month',TIMESTAMP '2017-09-30'); ``` Output: ```text date_part ----------- 9 (1 row) ``` ### 5) Extracting a decade from a timestamp The following example uses the `DATE_PART()` function to extract the decade from a timestamp: ```sql SELECT date_part('decade',TIMESTAMP '2017-09-30'); ``` Output: ```text date_part ----------- 201 (1 row) ``` ### 6) Extracting a week number from a timestamp To extract the week number from a time stamp, you pass the week as the first argument: ```sql SELECT date_part('week',TIMESTAMP '2017-09-30'); ``` Output: ```text date_part ----------- 39 (1 row) ``` ### 7) Extracting a week number from a timestamp To get the current millennium, you use the `DATE_PART()` function with the [`NOW()`](https://neon.com/postgresql/date-functions/postgresql-now) function as follows: ```sql SELECT date_part('millennium',now()); ``` Output: ```text date_part ----------- 3 (1 row) ``` ### 8) Extracting day from a timestamp To extract the day part from a timestamp, you pass the `day` string to the `DATE_PART()` function: ```sql SELECT date_part('day',TIMESTAMP '2017-03-18 10:20:30'); ``` Output: ```text date_part ----------- 18 (1 row) ``` ### 9) Extracting hour, minute, and second from a timestamp To extract the hour, minute, and second, from a time stamp, you pass the corresponding value hour, minute, and second to the `DATE_PART()` function: ```sql SELECT date_part('hour',TIMESTAMP '2017-03-18 10:20:30') h, date_part('minute',TIMESTAMP '2017-03-18 10:20:30') m, date_part('second',TIMESTAMP '2017-03-18 10:20:30') s; ``` Output: ``` h | m | s ----+----+---- 10 | 20 | 30 (1 row) ``` ### 10) Extracting day of the week, day of the year from a timestamp To extract the day of the week and or day of the year from a time stamp, you use the `dow` and `doy` arguments: ```sql SELECT date_part('dow',TIMESTAMP '2017-03-18 10:20:30') dow, date_part('doy',TIMESTAMP '2017-03-18 10:20:30') doy; ``` Output: ``` dow | doy -----+----- 6 | 77 (1 row) ``` ## Summary - Use the PostgreSQL `DATE_PART()` function to extract a subfield of a timestamp. --- ## Related docs (Date Functions) - [AGE](https://neon.com/postgresql/date-functions/age) - [AT TIME ZONE Operator](https://neon.com/postgresql/date-functions/at-time-zone) - [CLOCK_TIMESTAMP](https://neon.com/postgresql/date-functions/clock_timestamp) - [CURRENT_DATE](https://neon.com/postgresql/date-functions/current_date) - [CURRENT_TIME](https://neon.com/postgresql/date-functions/current_time) - [CURRENT_TIMESTAMP](https://neon.com/postgresql/date-functions/current_timestamp) - [DATE_TRUNC](https://neon.com/postgresql/date-functions/date_trunc) - [EXTRACT](https://neon.com/postgresql/date-functions/extract) - [ISFINITE](https://neon.com/postgresql/date-functions/isfinite) - [JUSTIFY_DAYS](https://neon.com/postgresql/date-functions/justify_days) - [JUSTIFY_HOURS](https://neon.com/postgresql/date-functions/justify_hours) - [JUSTIFY_INTERVAL](https://neon.com/postgresql/date-functions/justify_interval) - [LOCALTIME](https://neon.com/postgresql/date-functions/localtime) - [LOCALTIMESTAMP](https://neon.com/postgresql/date-functions/localtimestamp) - [MAKE_DATE](https://neon.com/postgresql/date-functions/make_date) - [MAKE_INTERVAL](https://neon.com/postgresql/date-functions/make_interval) - [MAKE_TIME](https://neon.com/postgresql/date-functions/make_time) - [NOW](https://neon.com/postgresql/date-functions/now) - [PG_SLEEP](https://neon.com/postgresql/date-functions/pg_sleep) - [STATEMENT_TIMESTAMP](https://neon.com/postgresql/date-functions/statement_timestamp) - [TIMEOFDAY](https://neon.com/postgresql/date-functions/timeofday) - [TO_DATE](https://neon.com/postgresql/date-functions/to_date) - [TO_TIMESTAMP](https://neon.com/postgresql/date-functions/to_timestamp)