So if I run the SQL now, it should give me sep 30 2012. millenium. Also, you need to study the week in snowflake. pyspark. The general idea is to get the current day of the week, dow, subtract 7, and take the abs, which will give you the number of days till the end of the week, and add 1, to get to Monday. The trunc () function is a mathematical function present in PostgreSQL. PostgreSQL uses 4 bytes to store a date value. Use the DATE_TRUNC() function if you want to retrieve a date or time with a specific precision from a PostgreSQL database. When used to aggregate data, it allows you to find time-based trends like daily purchases or messages per second. (Values of type date and time are cast automatically to timestamp or interval, respectively. It shows a similar result, converting the date to a month and year value, which changes the day to the first of that month. 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. date; The results:By implementing the feature above, we are going to learn the following date functions in PostgreSQL: Truncate date with date_trunc; Extract date parts, such as weekday, month and year with date_part. ) field selects to which precision to truncate the input value. 1 starts: 9. Section 9. For a date column: SELECT * FROM tbl WHERE my_date BETWEEN date_trunc('month', now())::date - 1 AND now()::date You can subtract plain integer values from a date (but not from a timestamp) to subtract days. 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¶. 9. sql. DATE '2000-01-02'. Args:. g. I am converting a postgres app to an Oracle app. select date_trunc ('minute', created_at), -- or hour, day, week, month, year count(1) from users group by 1. 5. In fact extract() gets re-written to date_part() - check the execution plan and you will see. DATE_DIFF. ). Use the date_trunc method to truncate off the day (or whatever else you want, e. date_trunc. 9. This is the query: select to_char (calldate,'Day') as Day, date_trunc (calldate) as transdate, Onnet' as destination,ceil (sum (callduration::integer/60. 9. md","path":"README. date_trunc('hour', interval '2 days 3 hours 40 minutes') 2 days 03:00:00:. 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. The DATE_TRUNC function is useful when. The DATE type in PostgreSQL can store a date without an associated time value: PostgreSQL uses 4 bytes to store a date value. But there is also no point in casting date literals to date as input parameter. date_trunc ('hour', created) + extract (minute from created)::int / 15 * interval '15' minute. Because that’s the way it’s implemented in Postgres and DB2. date_trunc¶ pyspark. How can i get. Return value. Let’s add a year to any date. 31 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. These. The week number will be in the range of 1 to 53, depending on the specific date and the datestyle setting in PostgreSQL. The DATE_TRUNC () function in Postgres truncate a date or time value to a specific precision. Chapter 9. The LOCALTIME function takes one optional argument:. Date_selector >) AS ddate, SUM (value1) AS value1FROM `project. 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. 2 Answers. SELECT DATE_TRUNC('quarter', TIMESTAMP '20200430 04:05:06. 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. These SQL-standard functions all return values based on the start time of the. g. It puts that value in. For example, decade 201 spans from 2000-01-01 to. 9. Sorted by: 2. 9. for example 2018-10-15 will be 2018-10-01 and 2018-10-30 also will be 2018-10-01. GROUP BY 1. SELECT id, name, date_trunc('quarter', date) AS date, AVG(rank) AS rank,. create table. 4. In order to group our orders by month, in PostgreSQL we'll use the date_trunc built-in function. このクエリを実行すると以下の結果が得られる。. 9. The subtraction of timestamps yields an interval. One way to do this is to "truncate" the date to the start of the month, then add 8 days: vardate := date_trunc ('month', vardate)::date + 8; date_trunc returns a timestamp that's why the cast ::date is needed. Delaying Execution. Realizing this is an old answer, but I recently ran into this. 9. Apr 20, 2017 at 8:39. 1-19ubuntu1) 10. See the example below to see how you can aggregate by MONTH: SELECT SUM(number) AS total, DATE_TRUNC (date, MONTH) AS month FROM ( SELECT CAST('2021-02-04' AS DATE) AS date, 3 AS number UNION ALL ( SELECT. Sorted by: 2. DATE_TRUNC. SPLIT_PART. Now, let us see the Date/Time operators and Functions. If the value is negative, the parts are counted backward from the end of the string. 3. Table 9. Use the aggregate FILTER clause in Postgres 9. That will give us an integer that's a multiple of 7. These SQL-standard functions all return values based on the start time of the current. Current Date/Time. EXTRACT, date_part. Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to. SELECT EXTRACT (YEAR FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 2001. character (the_year)) before you can concatenate it. Recently, I have been getting familiar with PostgreSQL(using 8. date_trunc函数根据指定的日期部分（例如小时、周或月）截断一个TIMESTAMP或一个INTERVAL值，并以一定精度返回截断的时间戳或间隔值。[email protected]_trunc ('month',current_date) + interval '1 month' - interval '1 day'. start }}'::timestamp) The result of that is a timestamp from which you can subtract the interval: date_trunc. Also, I'm leaving out '10:00'. 9. timestamp '2001-09-29 03:00' - timestamp '2001-09-27 12:00'. 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. The DATE type in PostgreSQL can store a date without an associated time value: PostgreSQL uses 4 bytes to store a date value. date_dim_id INT NOT NULL, date_actual DATE NOT NULL, epoch BIGINT NOT NULL, day_suffix VARCHAR(4) NOT NULL, day_name. 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. com PostgreSQL version: All Operating system: All Description: date_trunc('quarter',. This list of the. The second is more concise, but Postgres-specific. g. 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. What I need is to "round down" the month to day one, and I. Extracting year from a timestamp: SELECT EXTRACT(YEAR. SELECT date_trunc. I think the :: operator is more common in "Postgres land". 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 :. 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. The output shows that the current system hour from the timestamp value is 14. 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. SELECT EXTRACT(quarter FROM '2015-01-01'::timestamp) - 1; Result : 0 The most frequently used Postgres date functions and business scenarios where they come in handy: Rounding off timestamps with DATE_TRUNC function. 9. Takes two arguments, the date to truncate and the unit of. LastAccessDate), quarter = DATETRUNC(QUARTER,. How to write the query to get the first and last date of a January and other month's in postgresql 1 Get the timestamp of the last and first day of a month in postgresSQLIn order to ignore seconds, you can use date_trunc () function. 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. Table 9. Part of AWS Collective. Finding the last date of the previous quarter from current date in PostgreSQL Ask Question Asked 477 times 0 For example: If my current date is 2022. 662522'); You can also use the date_trunc () function truncate a value of type interval, for. 参数 field. The second one which use DATE_TRUNC will tranc any date to the first day of the month. Same as YEAROFWEEK, except uses ISO semantics. 摘要：本教程向您展示如何使用 PostgreSQL 的date_trunc()函数，将时间戳或间隔值截断到指定的精度级别。 PostgreSQL date_trunc 函数简介. created), 'YYYY-MM-DD')) GROUP BY d. PostgreSQL - DATE/TIME Functions and Operators. (. 24: In Postgresql, to truncate or extract the week of the timestamp value, pass the week as a string to the date_trunc function. 1 year and 2 months. Ask Question Asked 10 years, 5 months ago. The cast to date ( day::date) does that implicitly. Practical examples would include analyzing company’s quarterly. A primer on working with time in Postgres. 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. These SQL-standard. INTERVAL '1-2' YEAR TO MONTH. Rabbit. Use the function date_trunc() instead,. 9. Postgres has date_trunc which operates on timestamp or interval, and:. EXTRACT, date_part EXTRACT(field FROM source) The extract function retrieves subfields such as year or hour from date/time values. For data type TIMESTAMP WITH LOCAL TIME ZONE this function is calculated within. quarter: Quarter (1 to 4) second: Seconds (and fractional. The PostgreSQL formatting functions provide a powerful set of tools for converting various data types (date/time, integer, floating point, numeric) to formatted strings and for converting from formatted strings to specific data types. Select Query SELECT (date_trunc('MONTH', now()) + INTERVAL '1 MONTH -. ) field is an identifier or string that selects what field to extract. 1) below the day precision (first parameter) the time zone offset of the result is always the same as the second parameters' offset. AT TIME ZONE. date_trunc. date 、 time 、または timestamp を指定された精度に切り捨てます。. SELECT current_date + cast (abs (extract (dow FROM current_date) - 7) + 1 AS int); works, although there might be more elegant ways of doing it. You can also add the full timezone name as a third argument. Be aware of corner case pitfalls with type timestamp (or date ) depending on the current time zone setting (as opposed to timestamptz ). Current Date/Time. Gets the number of intervals between two DATE values. PostgreSQL provides a number of functions that return values related to the current date and time. Stack Overflow. Below query is working to get weekly summary. In the above output, it shows the output like a day of the timestamp value but we can find the week number. Format date with to_char; Setup. 使用函数截取日期的年份 要截取一个日期的年份，我们可以使用extract函数。1. So first the timestamp is converted to a date (that does not have a time), and then the time value is added to that, which yields a timestamp. values date_trunc ('HOUR', TIMESTAMP ('2017-02-14 20:38:40. In certain cases, it can also speed up some of your queries. The DATE_TRUNC () function is particularly useful for time series analysis to understand how a value changes over time. DROP TABLE if exists d_date; CREATE TABLE d_date. EXTRACT, date_part EXTRACT (field FROM source) The extract function retrieves subfields such as year or hour from date/time values. We are also looking at upgrading to a newer version of Postgres but that is further out. The Oracle code that I posted returns april 22, so I need postgres to do the same. The date_trunc function in redshift is specifically used to truncate the specified precision. 9. 31 shows the available functions for date/time value processing, with details appearing in the following subsections. I am trying to use the Date_Trunc for MONTH function in a SQL statement but somehow it is not working for me. It also uses this format for inserting data into a date. The quarter of the year (1 - 4) that the day is in. Values of type date and time are cast automatically to timestamp or interval, respectively. GROUP BY date_trunc('day', datelocal) ORDER BY date_trunc('day', datelocal); A bit more noisy code, but faster (and possibly easier to optimize for the query planner, too). Current Date/Time. You can truncate the current date to its quarter, then remove 1 day from that (and potentially cast back to date): -- You really only need the last column, the other two just show the different steps in the process SELECT DATE_TRUNC ('quarter', CURRENT_DATE) , DATE_TRUNC ('quarter', CURRENT_DATE) - '1 day'::INTERVAL. I have an sql query am trying to make to my postgres db. Syntax: date_trunc ('datepart', field) The datepart argument in the above syntax is used to truncate one of the field ,below listed field type: millennium. Also, you need to study the week in snowflake. 30 shows the available functions for date/time value processing, with details appearing in the following subsections. SELECT * FROM generate_series(date_trunc('quarter', '2008-02-01 00:00'), '2009-01-01 12:00', '3 months');. Any valid year (e. source must be a value expression of type timestamp, time, or interval. Like for example, I passed a date as on 12th January, 2015, I need the result to be as 4th quarter of 2014. DATE_TRUNC returns a date or timestamp, while DATE_PART returns a subfield from a date or timestamp. Showing an example based on the output you've outlined. demo:db<>fiddle. 1994-10-27. 'QUARTER': truncate to the first date of the quarter. column. Definition of PostgreSQL Trunc () PostgreSQL’s trunc () function is used to truncate the decimal places to a certain precision. To see the objects provided by the extension, run dx+ orafce. Share. 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. ; part_number (required): Requested part of the split (1-based). try this : SELECT datepart (quarter,transaction_date), count (distinct UNIQUE_ID) as cnt FROM panel WHERE (some criteria = 'x') GROUP BY datepart (quarter,p. Example 3:. GitHub Gist: instantly share code, notes, and snippets. yosihisa@jp. The EXTRACT() function returns a double precision value. Adding a month gives you the first of the following month. date_trunc is only defined for timestamp with time zone and timestamp inputs. md","contentType":"file"},{"name":"Script-CREATE-TABLE-dim_date. For more information, see TRUNC function. Use the below aggregate function with date_trunc and to_char function to use group by day in PostgreSQL. 1 Answer. century. datepart and timestamp, and. 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. Postgres has plenty of date-specific functions -- from date_trunc() to age() to + interval-- to support dates. select to_char (date_trunc ('month', l. The date_trunc function in redshift is specifically used to truncate the specified precision. date_trunc ( field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. Introduction to the PostgreSQL DATE_PART function. The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. What it does: The Redshift add_months function adds months, specified by integer to a date value. date_trunc (format: str, timestamp: ColumnOrName) → pyspark. Truncating any date or timestamp to the month level will give you the first of the month containing that date. Subtracts a specified time interval from a DATE value. The lowest and highest values of the DATE data type are 4713 BC and 5874897 AD. transaction_date) but the count (distinct) will do a sort so it will take you a lot of time. PostgreSQL 13. One truncates a date to the precision specified (kind of like rounding, in a way) and the other just returns a particular part of a datetime. , “Year” in the above example) to their initials. 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. source is a value expression of type timestamp or interval. source must be a value expression of type timestamp, time, or interval. date_trunc ( field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. In addition to these functions, the SQL OVERLAPS operator is supported: ( start1, end1 ) OVERLAPS ( start2, end2 ) ( start1, length1 ) OVERLAPS ( start2, length2 ) This expression yields true when two time periods (defined by their endpoints) overlap, false when they do not overlap. If you want just the date in the current time zone, cast to a date. 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'. Sorted by: 3. 8. As far as I understand you want to change the day of the month to 8. Adds a specified time interval to a DATE value. Date_trunc. LOCALTIME(precision) Arguments. source must be a value expression of type timestamp, time, or. 5. 1+) that I've overlooked. The function date_trunc is conceptually similar to the trunc function for numbers. A general solution for any time interval can be based on the epoch value and integer division to truncate. ) Details: 'quarter' is not mentioned in the doc as valid fields for date_trunc(). The format of the date in which it is stored and retrieved in PostgreSQL is yyyy-mm- dd. 2 Answers. Note that to_date () returns a date so your code would remove the just added time part again. DATE_TRUNC is very handy for aggregating your data by a particular date_part, like MONTH. age; current_date; current_time; current_timestamp; date_part; extract; localtime;. Date_selector >) AS ddate, SUM (value1) AS value1FROM `project. ) as we did for the EXTRACT code. 6. orafce should be among them. Follow answered Jun 19, 2013 at 9:23. A weird way to number weeks but might be what the OP is after :) – Andomar. The quarter of the year (1–4) that the date is in. PostgreSQL has several of functions for manipulating the dates such as extracting. It’s possible in Postgres to truncate or round a given timestamp to some given level of precision. I am using this script to create and populate a partly localized (for Turkish) date dimension table. 27 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. Postgres では、特定のタイムスタンプを特定のレベルの精度に切り詰めたり丸めたりすることができます。. It’s possible in Postgres to truncate or round a given timestamp to some given level of precision. For formatting date/time values for display, see Section 4. 9. The DATE_TRUNC () function is used to truncate a date, time, or timestamp to a specified interval, such as the day, week, or month, in PostgreSQL and SQL. These SQL-standard functions all return values. When storing a date value, PostgreSQL uses the yyyy-mm-dd format e. To generate a series of dates this is the optimal way: SELECT t. I assume this is for analytics purpose. Split a string on a specified delimiter and return nth substring. Table 9. We had discussed about the Date/Time data types in the chapter Data Types. Postgres 13 or older. The precision parameter is case-insensitive. 2: I've chosen "date_period" to be just one day (and, in some places, formatted the result for ease of display). The syntax of the function is as follows: DATE_TRUNC ('precision', expression); where expression is a timestamp or an interval to truncate. Based on the parts extracted, create a new datetime. The time zone. date_trunc¶. I am thinking of defining variables with reference to current date. PostgreSQL provides a number of functions that return values related to the current date and time. Sorted by: 1. 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:. trunc; Date/Time Functions. The following are valid field names. trunc (teste TIMESTAMP WITHOUT TIME ZONE). Here is how I make a standard quarterly score average with default quarter. I would suggest not thinking too hard about the problem and just using the first date/time of the month. date 、 time 、または timestamp を指定された精度に切り捨てます。. 2020-04-01 , and has the advantage that subsequent steps in the pipeline can read it like a normal date. In this article I will go over the three date/time related data types, and the two most useful date/time functions…postgresql error: function date_trunc(unknown, text) does not exist LINE 1 #9783. Ordering by month & year numbers in Postgres. We’ll use it for different. , year, month, week from a date or time value. These SQL-standard functions all return values based on the start time of the current transaction:DATE_TRUNC. Postgres examples include comparing years, quarters, day of week and rolling time periods. 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. , hour, week, or month and returns the truncated timestamp or interval with a level of precision. EXTRACT (MONTH FROM input) AS "Month". Note that the specifier is a string and needs to be enclosed in quotes. You should be familiar with the background information on date/time data types from. Previous: DATE_TRUNC function Next:. Posted on July 24, 2020 by Ian In PostgreSQL, the date_trunc () function truncates a date/time value to a specified precision. Optional. Ex:If I have 2010-01-01, I would like to return 2010-03-31, and so on. 16. 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. ). parse_datetime(string, format) → timestamp with time zone. If there are really 250000 different days in your table, you probably cannot do much better than this. 4. confusingly at time. Below is the example, and the syntax of the date_trunc function is as follows. In simple terms,. PostgreSQL provides a number of functions that return values related to the current date and time. Truncate it to the start of the day (still timestamp without time zone ): date_trunc ('day', (now () AT TIME ZONE 'America/New_York')) Get the. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. Teams. For a more comprehensive guide. Date/Time Functions. When working with dates and times in PostgreSQL, having a date calendar table can be incredibly useful. The second one which use DATE_TRUNC will tranc any date to the first day of the month. CREATE OR REPLACE FUNCTION last_day(date) RETURNS date AS $$ SELECT (date_trunc('MONTH', $1) + INTERVAL. Dates are stored using the DATE datatype in the PostgreSQL database. You can update the type of the column like this: ALTER TABLE your_table ALTER COLUMN tservice TYPE date; and then add the constraint like so:There are various DateTime functions as well as operators availabe in PostgreSQL. Both interval and date_trunc have helped me write more effective SQL queries and answer thorny questions about app data. +01 +02 etc depends on your time locale's daylight saving rules. 9. 9. You are correct, I meant quarter, but typed month. “Year” must be passed. 9. 9. DATE 'YYYY- [M]M- [D]D'. This function can also truncate a number. They both do very different things. 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. ). Data warehouse support for the EXTRACT function Google BigQuery, Amazon Redshift, Snowflake, Postgres, and Databricks all support. The following table lists the behaviors of the basic arithmetic operators −. Adding date_trunc('quarter', your_date) to your start date will guarantee you start with the beginning of a quarter. To return. PostgreSQL DATE_PART examples. Now, let us see the Date/Time operators and Functions. Here's the best GROUP BY query I have so far: SELECT d. These SQL-standard functions all return values based on the start time of the current transaction:QUARTER: The calendar quarter of the specified date as an integer, where the January-March quarter is 1. Here’s the current timestamp. 8. The DATE_PART () function extracts a subfield from a date or time value. 2017) YEAROFWEEKISO. Both solutions include the last day of the previous month and also include all of "today". It's best explained by example: date_trunc('hour',TIMESTAMP '2001-02. DATE_SUB. 4. To have one row per minute, even when there's no data, you'll want to use generate _ series. It takes a date part (like a decade, year, month, etc. Based on the parts extracted, create a new datetime. Sorted by: 3. Covers all your examples. e. The PostgreSQL formatting functions provide a powerful set of tools for converting various data types (date/time, integer, floating point, numeric) to formatted strings and for converting from formatted strings to specific data types. region, q1. 2) and found the date_trunc function extremely useful for easily matching time stamps between certain days/months/etc. Working with Dates (SQL) - EXTRACT, DATE_PART, DA…How to truncate date in PostgreSQL? Ask Question Asked 10 years, 2 months ago Modified 10 years, 2 months ago Viewed 42k times 22 I'm trying to select all. - It retrieves the trimmed part with a specific precision level. RTRIM. If you prefer to write standard SQL, stick to extract(). The GROUP BY clause in Postgres allows us to group the table’s data based on specific column(s), making it easy to analyze and understand relationships and patterns within your data. They both do very different things. Postgres Pro provides a number of functions that return values related to the current date and time. 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. As shown in the results, the hours and above are preserved, while the minutes and seconds is truncated. SELECT TRUNC(datevalue, 'MONTH') FROM datelist; Result: 01/MAR/22. date_trunc () The return type of the date_trunc function is a timestamp. 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. A similar functionality provides the Oracle compatible function TRUNC [ATE] (datetime). WHERE date_survey >= date_trunc('year', now()); Or maybe add EXTRACT('quarter' FROM date_survey) AS start_season to add the quarter number. One possibility: select year * '1 year'::interval + '0000-01-01'::date; I like this way because it avoids conversion between text and integer (once all the constants are parsed). 3 Answers. pto_start_date < (date_trunc ('quarter', now () - INTERVAL '1 month') + INTERVAL. , ‘year’, ‘quarter’, ‘month’, ‘day’, ‘hour’, ‘minute’, ‘second’, etc. g.