From the documentation: date_part (): The date_part function is modeled on the traditional Ingres equivalent to the SQL-standard function extract:Into something like: SELECT COUNT (*) = 1 INTO v_exists FROM pg_tables WHERE schemaname = 'public' AND tablename = v_partition_name and v_date_from < date_trunc ('year', current_date); This will return 1 only in the case when partition is from previous year. What I want instead is a function that takes three parameters, so I could do make_date(2000, 1, 2) and use integers instead of strings, and returns a date (not a string). 5. in general, in group by queries, does it matter whether using - functions on the date - a day table that has extraction pre-calculated. example: SELECT date_trunc ('hour', time 'columnName') from tableName. g. Yes, that is how you use date_trunc. 662522'); You can also use the date_trunc () function truncate a value of type interval, for. The range of values for date values in PostgreSQL is 4713 BC to 5874897 AD. g. ) Example of grouping sales from orders by month: select SUM(amount) as sales, date_trunc('month', created_at) as date from orders group by. All the functions and operators described below that take time or timestamp inputs actually come in two variants: one that takes time with time zone or timestamp with time zone, and one that takes time without time zone or timestamp without time zone. In Postgresql, we can also add a year to the current date using the INTERVAL data type. In the following example, DATE_TRUNC retrieves the beginning of the current month, adds one month to retrieve the beginning of the next month, and then subtracts 1 day to determine the last day of the current month. Truncates a DATE value. This is one way to go about it. id, generate_series(well_schedules. This is not by any means an exhaustive guide to date and time expressions in BigQuery. 0. This function truncates a date/time value to a specified precision. PostgreSQL 13. Special calculation is needed for week/quarter. reply. For example, if we want to truncate the date and time value to the nearest hour or week, it is possible to truncate using the date_trunc function. You can also add the full timezone name as a third argument. A function for truncating a time value to a specified unit. CREATE OR REPLACE FUNCTION round_time (timestamp with time zone) RETURNS timestamp with time zone AS $$ SELECT date_trunc ('hour', $ 1) + interval '5 min' * round (date_part ('minute', $ 1) / 5. It takes a date part (like a decade, year, month, etc. 2. SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 1 second. ) field selects to which precision to truncate the input value. 8. , for the Oracle database: sale_date >= TRUNC (sysdate) AND sale_date < TRUNC (sysdate + INTERVAL '1' DAY) Another common obfuscation is to compare dates as strings as shown in the following PostgreSQL example:6. Current Date/Time. PostgreSQL DATE_PART () function is mainly used to return the part of the date and time; the date_part function in PostgreSQL will subtract the subfield from the date and time value. 9. shahkalpesh. SELECT date_trunc. Adding date_trunc('quarter', your_date) to your start date will guarantee you start with the beginning of a quarter. WW truncates date to the nearest previous day same to the first day of week of the year. A bigint is not "a timestamp", so you must convert the number to a date before you can apply date_trunc () on it: Select date_trunc ('day', to_timestamp (rp. SELECT SUM(orders. Extract QUARTER from Timestamp in Postgresql: Within the Extract keyword we have to mention QUARTER as we are getting quarter from timestamp. Postgres 13 or older. Its type is timestamp without time zone. New in version 2. 2020-04-01 , and has the advantage that subsequent steps in the pipeline can read it like a normal date. Let's see: = $ SELECT date_bin ('5 minutes', now ()); ERROR: FUNCTION date_bin (UNKNOWN, TIMESTAMP WITH TIME zone) does NOT exist. g. 9. The PostgreSQL date_part function extracts parts from a date. Note that the specifier is a string and needs to be enclosed in quotes. 9. But almost all SQL databases support these in some form or another. Here’s an example that returns the last day of the current month: SELECT (date_trunc ('month', now ()) + interval '1 month - 1 day'); Result: 2022-04-30 00:00:00+10. Add a comment. If I use the below query, I get the result as 0. The quarter of the year (1–4) that the date is in. format_datetime(timestamp, format) → varchar. Assuming you want all "overlapping" time periods, i. If you want both quarter and year you can use date_trunc: SELECT date_trunc('quarter', published_date) AS quarter This gives the date rounded to the. Part of AWS Collective. (Values of type date and time are cast automatically to timestamp or interval, respectively. Be aware of corner case pitfalls with type timestamp (or date ) depending on the current time zone setting (as opposed to timestamptz ). The following are a couple custom functions which allow this configuration. 9999999 which your desired condition would not include). g. Connect and share knowledge within a single location that is structured and easy to search. Learn more about TeamsThis can be broken down into 4 steps: Take the current timestamp with time zone: now () Get the according local timestamp without time zone for New York: now () AT TIME ZONE 'America/New_York'. In Postgres, DATE_TRUNC () has the following intervals. PostgreSQL provides a number of functions that return values related to the current date and time. ) and a TIMESTAMP as parameters, and then it truncates the TIMESTAMP according to the specified date part. - The value for the “field” argument must be valid. RTRIM. There is no function you want, but as said in postgresql wiki you can define function for youself: CREATE OR REPLACE FUNCTION round_time_10m (TIMESTAMP WITH TIME ZONE) RETURNS TIMESTAMP WITH TIME ZONE AS $$ SELECT date_trunc ('hour', $1) + INTERVAL '10 min' * ROUND (date_part ('minute', $1) / 10. The first removes the hours and smaller units from the timestamp, but still returns a timestamp, while the latter returns the timestamp cast to a date. , ‘year’, ‘quarter’, ‘month’, ‘day’, ‘hour’, ‘minute’, ‘second’, etc. SELECT DATE_TRUNC('quarter', TIMESTAMP '20200430 04:05:06. These SQL-standard functions all return values. A função DATE_TRUNC do Postgres pode nos ajudar a “truncar” uma data, bem, mas o que isso quer dizer? É simples, ela retorna a data inicial de um intervalo. 1) precision The precision argument specifies fractional seconds precision of the second. Table 9. string_text (required): Text to be split into parts. 6. time_zone. Syntax: date_trunc. com PostgreSQL version: All Operating system: All Description: date_trunc('quarter',. 0. SELECT EXTRACT(QUARTER FROM TIMESTAMP '2023-03-11 17:43:17. to_char and all of the formatting functions let you query time however you want. Interprets an INT64 expression as the number of days since 1970-01-01. note: similar question as DATE lookup table (1990/01/01:2041/12/31). 330202+05:30”. Let’s add a year to any date. Note that the latter. 2: I've chosen "date_period" to be just one day (and, in some places, formatted the result for ease of display). DATE_TRUNC. TRUNC(date, format) Code language: SQL (Structured Query Language) (sql) Arguments. Take two easy steps to create date_trunc: Break down the datetime into small parts (Year, Month, Day/Hour, Minute, Second) and extract the parts you need. Table 9. For formatting functions, refer to Section 9. In the above output, it shows the output like a day of the timestamp value but we can find the. values date_trunc ('MONTH', DATE ('2007-02-18')) Result: 2007-02-01 00:00:00. For example. e. date 、 time 、または timestamp を指定された精度に切り捨てます。. date=to_char (date_trunc ('day', se. Remove the longest string that contains specified characters from the right of the input string. The subtraction of timestamps yields an interval. Sorted by: 2. DATE_DIFF. 日付や時刻を指定のところ（精度といいます）で切り捨てるには、 date_trunc関数 を使います。. 9. For example, decade 201 spans from 2000-01-01 to. "deleted_at" IS NULL). In order to group our orders by month, in PostgreSQL we'll use the date_trunc built-in function. split_part . Here's an example: SELECT round (date_trunc ( 'day', your_date_column):: date) AS rounded_date FROM your_table; In this example, replace your_date_column with the actual name of the column that contains the date you want to round, and your_table with the name of the table where the column resides. 789'); date_trunc 2020-04-01 00:00:00 Truncate the input timestamp to the first day of a year. As one gets converted to the other, there is absolutely no performance difference. AS day_of_month, datum - DATE_TRUNC('quarter',datum)::DATE +1 AS day_of_quarter, EXTRACT. RPAD (‘ABC’, 6, ‘xo’) ‘ABCxox’. - It accepts a “datePart” and a “field” as arguments. 9. PostgreSQL での DATE_TRUNC () 関数の使用. Improve this answer. 1994-10-27. Well, In postgres, it seems there's no such function equivalent to LAST_DAY() available in oracle. Table 9. Share. Pad on the right of a string with a character to a certain length. DATE_TRUNC() will return an interval or timestamp rather than a number. SELECT date_trunc('year', TIMESTAMP '2022-05-16 12:41:13. Realizing this is an old answer, but I recently ran into this. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. If you do want to use BETWEEN (which will only work properly if date is defined with the data type date) then you can use: select * from my_table where date between date_trunc ('year', current_date - interval '1 year')::date and date_trunc ('year', current_date)::date - 1. I think the :: operator is more common in "Postgres land". 9. The DATE_TRUNC () function is particularly useful for time series analysis to understand how a value changes over time. You would need to use to_timestamp () if you really want. PostgreSQL's date_trunc in mySQL Ask Question Asked 12 years, 7 months ago Modified 10 months ago Viewed 43k times 26 Recently, I have been getting familiar. The DATE type in PostgreSQL can store a date without an associated time value: PostgreSQL uses 4 bytes to store a date value. Use the date_trunc () function to get the first day of the quarter and then subtract one day. From the documentation: date_part (): The date_part function is modeled on the traditional Ingres equivalent to the SQL-standard function extract: 2. Since this is a performance-critical part of the query, I'm wondering whether this is the fastest solution, or whether there's some shortcut (compatible with Postgres 8. To generate a series of dates this is the optimal way: SELECT t. +01 +02 etc depends on your time locale's daylight saving rules. The function date_trunc is conceptually similar to the trunc function for numbers. SELECT date_trunc. 9. For example, if we want to truncate the date and time value to the nearest hour or week, it is possible to truncate using the date_trunc function. Take two easy steps to create date_trunc: Break down the datetime into small parts (Year, Month, Day/Hour, Minute, Second) and extract the parts you need. yosihisa@jp. the Use of the DATE_TRUNC() Function in PostgreSQL. Date_selector >) AS ddate, SUM (value1) AS value1FROM `project. Try to envision time periods on a straight time line and move them around before your eyes and you will see the necessary conditions. Be aware of corner case pitfalls with type timestamp (or date ) depending on the current time zone setting (as opposed to timestamptz ). date_trunc¶ pyspark. SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 1. date_trunc will truncate a date or timestamp to the specified date/time part. 4. How can i get. Right now the cod. SELECT DATE_TRUNC('minute', some_date) FROM some_table; This was working fine but I got to know that index made on some_date column will be futile because indexes doesn't work with DATE_TRUNC(), Index created was as follows :. "GROUP BY date_trunc also? @Bravo: yes you need to repeat the expression in the group by clause. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. Current Date/Time. #. 2 Answers. 必需的。 它是一个字符串表示要截取到部分。您可以是使用以下值： microseconds; milliseconds; second; minute; hour 1 Answer. 6. g. The date_part function is modeled on the traditional Ingres equivalent to the SQL -function extract: The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. g. I can get the quarter number and year: select to_char(date_trunc('quarter', current_date):: date, 'yyyy-q'); Which returns 2017-3 since today is 2017-07-14. date_trunc () is a system function for truncating a timestamp or interval to a specified unit. Any valid year (e. date_trunc will truncate a date or timestamp to the specified date/time part. 9. PostGreSQL : date_trunc() returns timestamp with timezone when used on date. These SQL-standard functions all return values based on the start time of the current. timestamp. Postgres has plenty of date-specific functions -- from date_trunc() to age() to + interval-- to support dates. RTRIM (‘abcxxzx’, ‘xyz’) ‘abc’. 16. I have been trying to simulate the following Oracle statement in PostgreSQL: To reach this, I was already able to simulate the TRUNC () function receiving only one time datatype parameter, which is timestamp without time zone. The query below shows sample data of your user adding an other user with a session over two days (to demonstrate the principle) The subquery day_cnt calculates the minimal start date of the sessions and the count_days that is covered with the sessions. (In our example, we used month precision. The DATE_TRUNC function is useful when. It is only meant as a quick reference to those I use most often. , hour, week, or month and. SELECT date_trunc ('quarter', now()); date_trunc-----2021-01-01 00:00:00+00. The output shows that the current system hour from the timestamp value is 14. Date Dimension for Postgres. Section 9. dayofweek_iso 部分は、 ISO-8601データ要素と交換形式の標準に従います。 この関数は、曜日を1-7の範囲の整数値として返します。1は月曜日を表します。 他のいくつかのシステムとの互換性のために、 dayofweek 部分は UNIX 標準に従います。 この関数は、曜日を整数値として0-6の範囲で返します。On 29/10/2018 16:26, Andreas Karlsson wrote: > On 10/29/2018 04:18 PM, Vik Fearing wrote: >> A use case that I see quite a lot of is needing to do reports and other >> calculations on data per day/hour/etc but in the user's time zone. 1. ). Delaying Execution. PostgreSQL provides a number of functions that return values related to the current date and time. SELECT TRUNC(datevalue, 'MONTH') FROM datelist; Result: 01/MAR/22. Note: All the date field parts other than the targeted. To group data by year, you can use the DATE_TRUNC function with ‘year’ as the first argument. Here’s a bit of code adapted from the PostgreSQL wiki that I like for creating the ever necessary date dimension in PostgreSQL. In other words we can use date_trunc for date values with a cast:. So if the date in the field input was 04/26/2016 this syntax returns 4,. Use the DATE_TRUNC() function if you want to retrieve a date or time with a specific precision from a PostgreSQL database. e. To see the schema where orafce is installed, use dx orafce. ). Now, let us see the Date/Time operators and Functions. Here’s the current timestamp. ) Details: 'quarter' is not mentioned in the doc as valid fields for date_trunc(). 0) $$ LANGUAGE sql; Pad on the right of a string with a character to a certain length. 8. 001 WHEN 'second' THEN 1. js ORM for postgreSQL), im trying to group by date range, and keep a count of how many items where in that table. What I need is to "round down" the month to day one, and I. Example 3. lead_id) as "# New Leads" from leads l where l. date_trunc () The return type of the date_trunc function is a timestamp. YEAR. order_date) AS interval FROM orders WHERE orders. functions. pyspark. This uses PostgreSQL’s date_trunc () function, along with some date arithmetic to return the results we want. edited Aug 18, 2015 at 10:57. What it does: The Redshift add_months function adds months, specified by integer to a date value. ) inside sql (. SELECT EXTRACT (QUARTER FROM TIMESTAMP '2011-11-22 13:30:15') So the resultant quarter will be EXTRACT QUARTER from Timestamp in column of Postgresql table:. Almost as it can't take any interval with units of months or more (due to varying duration). date_trunc('hour', interval '2 days 3 hours 40 minutes') 2 days 03:00:00:. For a more comprehensive guide. Try this one: select to_char (trunc_date,'FMMonth YYYY') from ( select distinct date_trunc ('month', orderdate) as trunc_date from table order by trunc_date desc ). create table. ; delimiter_text (required): Text representing the delimiter to split by. Update. The date_trunc function contains the two input parameters, i. LOCALTIME(precision) Arguments. I can't believe the accepted answer has so many upvotes -- it's a horrible method. date_trunc. But the week starts on Monday in Postgres by default. SELECT q1. 24')); Result: 2017-02-14 20:00:00. When using this function, do not think in terms of days. The quarter of the year (1 - 4) that the date is in SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 1. Table 9. PostgreSQL date_part function will allow retrieving subfields from the date and time value, e. 10. create or replace function what_quarter_is(date_in date, start_mon_in. Optional. I have an sql query am trying to make to my postgres db. The function date_trunc is conceptually similar to the trunc function for numbers. 3 Answers. You can then manipulate this output (with strftime. This query, for example, works, but as soon as I try a left join with a different table there is a problem: select date_trunc ('month',created_at)::date as date , id as id from promo_code_uses order by date DESC; sounds like created_at is a standard field in many of your tables. 9. PostgreSQLのTIMESTAMP型で値を入れた日時データについて、小数点以下の秒数を「切り捨て」して取得する方法を紹介する。 まずは結論から。 以下のとおり、 date_trunc 関数を使うことで小数点以下を「切り捨て」して取得することができる。In the docs I could only find a way to create a date from a string, e. 9. currently I am coding the exact date for the last quarter, the quarter before and the quarter one year ago. date_trunc (field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. is out of the question as this forces quarters to start on Jan 1st and it has 'hardcoded' quarter starting dates (Apr 1st, Jul 1st, etc). region, q1. It will return the date truncated to month precision, e. 1 to 31. Here is my solution adapted to the question given: SELECT DATE_TRUNC ('minute', NOW ()) - MAKE_INTERVAL (MINS => MOD (EXTRACT (MINUTE FROM NOW ())::INTEGER, 15)) Explanation: DATE_TRUNC the timestamp to. The real value returned by the CURRENT_TIMESTAMP was ‘2023-06-17. functions. AT TIME ZONE. たとえば、最も近い分、時間、日、月などに切り捨てることができます。. Add a comment. Based on the parts extracted, create a new datetime. When working with dates and times in PostgreSQL, having a date calendar table can be incredibly useful. PostgreSQL provides a number of different date and time functions by default that can be used to calculate these kinds of KPIs. SELECT cast (created_at as date) as created_at, count (created_at) FROM forms group by 1 ORDER BY created_at asc; If you want the date in a particular time zone, date_trunc with that time zone then cast to a date. If you pass a DATE value, the function will cast it to a TIMESTAMP value. 1. appointment_date::date + appointment_end_time::time. The special difficulty of your task: you want the ceiling, not the floor (which is much more common). The most frequently used Postgres date functions and business scenarios where they come in handy: Rounding off timestamps with DATE_TRUNC function. 3. EXTRACT, date_part EXTRACT(field FROM source)The extract function retrieves subfields such as year or hour from date/time values. It's bad practice but you might be forgiven if you use. Learn how to round or truncate timestamps in PostgreSQL for effective time-based grouping using the date_trunc function. When used to aggregate data, it allows you to find time-based trends like daily purchases or messages per second. 1 year and 2 months. In the above query within the date_part() function, provided the two values, the unit or the component ‘hour’ and the CURRENT_TIMESTAMP function that returns the current time your system. select * from table where extract (hour from column1) in (8, 9) where cast (column1 as time) >= '8:00' and column1::time < '10:00'. Share. Connect and share knowledge within a single location that is structured and easy to search. So using date_trunc ('week',now ())-'1 s'::interval; on the right side of your date operator should work. DATE_FROM_UNIX_DATE. The extract function is primarily intended for computational processing. By Admin August 9, 2023 August 9,. I am using this script to create and populate a partly localized (for Turkish) date dimension table. and source is the date. 9. If you need to, you can have your own in the following ways as a. A) Extracting from a TIMESTAMP examples. PostgreSQL date_trunc examples The following example truncates a TIMESTAMP value to hour date part: SELECT DATE_TRUNC( 'hour' , TIMESTAMP '2017-03-17 02:09:30' ); date_trunc¶. SELECT CASE WHEN created_at BETWEEN date_trunc. It's not immutable because it depends on the sessions time zone setting. The DATE_TRUNC () function in Postgres truncate a date or time value to a specific precision. both YEAR and YEARS are valid). Share. date_trunc (format, timestamp) [source] ¶ Returns timestamp truncated to the unit specified by the format. SELECT CODE, to_char (DATE, 'YYYY-MM'), count (CODE) FROM employee where group by CODE, to_char (DATE, 'YYYY-MM') Depending on whether you want the result as text or a date, you can also write it like this: SELECT CODE, date_trunc ('month', DATE), COUNT (*) FROM employee GROUP BY CODE, date_trunc ('month', DATE); Which in your. So if I run the SQL now, it should give me sep 30 2012. The basic syntax of the DATE_TRUNC function is as shown below: DATE_TRUNC(precision, source); where precision is the precision to which you want to. I assume this is for analytics purpose. For more information, see TRUNC function. ). You can now use date_trunc (text, timestamp) with Doctrine! Note: You can easily adapt this code for every additional Postgres/MySQL function. 2) and found the date_trunc function extremely useful for easily matching time stamps between certain days/months/etc. That will give us an integer that's a multiple of 7. character (the_year)) before you can concatenate it. Sorted by: 3. date_created >= { {date_range_start}} and l. 8. In PostgreSQL, DATE_TRUNC Function is used to truncate a timestamp type or interval type with specific and high level of precision. Syntax DATE_TRUNC(‘[interval]’, time_column) The time_column is the database column that contains the timestamp you'd like to round, and [interval] dictates your desired precision level. This is where PostgreSQL can help us with some date functions. SELECT date_trunc('week', date::date) AS "weekly", COUNT(DISTINCT(date)) AS "working_days" FROM "public". I'm looking for a single function which I can substitute for date_part in this query so that it returns 65: select date_part('minutes', '65 minutes'::interval);. or you can create your own. date_trunc('hour', interval '2 days 3 hours 40 minutes') 2 days 03:00:00:. date_trunc('field', source) source is a value expression of type timestamp (values of type date and time are cast automatically). Some common precisions are year, month, week, day, hour or minute. A weird way to number weeks but might be what the OP is after :) – Andomar. , hour, week, or month and returns the truncated timestamp or interval with a level of precision. The quarter of the year (1–4) that the date is in SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 1. PostgreSQL DATE_PART examples. 9. millenium. You can fix a date or remove days from current day. orafce should be among them. 'QUARTER': truncate to the first date of the quarter. Postgres has lots of functions for interval and overlap so you can look at data that intersects. trunc() will set that to 00:00:00 If you want a date/time value (=timestamp) where the time part is 00:00:00 then you can use current_date::timestamp or date_trunc('day', current_timestamp). Consequently, the timestamp will be rounded/truncated based on the specified date field. Your database returned: ERROR: set-returning functions are not allowed in CASE Hint: You might be able to move the set-returning function into a LATERAL FROM item. When storing a date value, PostgreSQL uses the yyyy-mm-dd format e. , 2000-12-31. Right now the cod. 指定した単位（month）以下の値が切り捨てられ、 年 月という結果. , hour, week, or month and returns the truncated. Use the below command: SELECT date_trunc ('week', timestamp'2021-08-23 19:14:20'); Postgresql date_trunc week. 'QUARTER' First day of its quarter. 28 shows the available functions for date/time value processing, with details appearing in the following subsections. Hey so im trying to query from a database, using Sequelize (Node. source is a value expression of type timestamp or interval. for example, in postgresql. 1. Some details are different for date or timestamptz. Recently, I have been getting familiar with PostgreSQL(using 8. The time zone. SQL Server: Date truncation for custom time periods like year, quarter, month, etc. SELECT distinct (CASE WHEN {PERIOD} = 'Previous Quarter' AND pto. (Values of type date and time are cast automatically to timestamp or interval, respectively. 4. Truncating any date or timestamp to the month level will give you the first of the month containing that date. This is how I made it: CREATE OR REPLACE FUNCTION public. The following illustrates the syntax of the date_trunc function: date_trunc ('datepart', field) Code language: SQL (Structured Query Language) (sql) date_trunc ( field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. INTERVAL allows either YEAR and MONTH to be mixed together or DAY, HOUR, MINUTE and SECOND. 1 Answer. the Use of the DATE_TRUNC () Function in PostgreSQL. Explore options like 'second', 'minute', 'hour', 'day', or 'month' to tailor your data analysis. CREATE INDEX ON. 31 shows the available functions for date/time value processing, with details appearing in the following subsections. If you prefer to write standard SQL, stick to extract(). To get week start and end date (as 0 for Monday and 4 for Friday): select cast (date_trunc ('week', current_date) as date) + 0 || '-->' || cast (date_trunc ('week', current_date) as date) + 4; 2015-08-17-->2015-08-21. --set the first day of the. Format date with to_char; Setup. Basically, there are two parameters we. Ask Question Asked 10 years, 5 months ago. Ordering by month & year numbers in Postgres. This function is most widely used for creating time series and aggregating at a granular level. GROUP BY 1. 6. Table 9-27 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. 2. Date: 20 July 2000, 05:00:19. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. 5. The following table lists the behaviors of the basic arithmetic operators −. com PostgreSQL version: All Operating system: All Description: date_trunc('quarter',. 1. PostgreSQL provides a number of functions that return values related to the current date and time. age; current_date; current_time; current_timestamp; date_part; extract; localtime;. ) Details: 'quarter' is not mentioned in the doc as valid fields for date_trunc(). 9. This can make date/time fields easier to read, as well as help perform cleaner time-based analyses. PostgreSQL has several of functions for manipulating the dates such as extracting. See the documentation for all values. That is easy enough to add. EXTRACT, date_part EXTRACT(field FROM source) The extract function retrieves subfields such as year or hour from date/time values. source must be a value expression of type timestamp, time, or interval. The quarter of the year (1 - 4) that the date is in SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 1. To verify that, connect to PostgreSQL with psql and run dx to list the extensions.