They are both the same. The syntax of the LOCALTIME function is as follows:. (In our example, we used month precision. Current Date/Time. 1+) that I've overlooked. ) field selects 9. 27. Summary: in this tutorial, we will introduce you to the PostgreSQL DATE_PART() function that allows you to retrieve subfields e. 0. The cast to date ( day::date) does that implicitly. milliseconds. I have a date field in a postgresql database (field name is input) how can I extract the month only from the date field? I used the syntax below, but I want it to show the actual month name, not a numeric value for the month. 0. 94. This function takes two arguments: the first is the end date and the second is the start date. This uses PostgreSQL’s date_trunc () function, along with some date arithmetic to return the results we want. ISFINITE. I have this problem. If the value is negative, the parts are counted backward from the end of the string. How to use the PostgreSQL Date Function: Date_Trunc. Multiply it by 1000 to turn it into milliseconds. date_trunc() in Postgres is the equivalent to trunc() for dates in Oracle - but it's not needed for date values in Postgres as a date does not contain a time part. return the average of 1:00 to 2:00. I made psql query but i need to convert it into typeorm code as i'm new to typeorm stack. Modified 10 years, 9 months ago. I. You're storing timestamps, not just dates, and you want to group by day not by number of previous events. 3 Answers. sql. PostgreSQL - DATE/TIME Functions and Operators. 5. 1) 2. Apparently, the PostgreSQL planner does not evaluate functions. The subtraction of timestamps yields an interval. Postgres: Update date and retain time from timestamp. ) in a Spring Boot application with Hibernate running on top of a Postgresql database. timestamp)) from rollup_days as rp; To convert the timestamp back to a bigint, use extract () Select date_trunc('week',dateTime) Date_week, Max(Ranking) Runing_Total_ID from (select datetime, id , dense_rank over (order by datetime) as Ranking from Table1) group by 1 This query is working for me to give me the running total of total IDs by week. So i used date_trunc () function to get this type of record. , date/time types) we describe the actual behavior in subsequent sections. ShareTeams. ). Truncate to specified precision. This function truncates a date/time value to a specified precision. "type. You can now use date_trunc (text, timestamp) with Doctrine! Note: You can easily adapt this code for every additional Postgres/MySQL function. This is a timestamp with time zone value which refers in fact to. 5. date_trunc can be really helpful if you want to roll up time fields and count by day or month. 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. g. Current Date/Time. date_trunc('hour', timestamp '2001-02-16 20:38:40') → 2001-02-16 20:00:00. ex: between 2013-04-07 15:30:00, 2013-04-07 15:40:00 5 results. 0. I need it to return april 22. (Values of type date and time are cast automatically to timestamp or interval, respectively. 2) and found the date_trunc function extremely useful for easily matching time stamps between certain days/months/etc. '2013-05-31 00:00:00'というような、. date_trunc. select * from table where extract (hour from column1) in (8, 9) where cast (column1 as time) >= '8:00' and column1::time < '10:00'. 31 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. So I have dates in a column for everyday with corresponding sales and I want to accumulate the sales for a week over a single date (say Friday). Now, let us see the Date/Time operators and Functions. So if the date in the field input was 04/26/2016 this syntax returns 4,. Code:The date/time functions provide a powerful set of tools for manipulating various date/time types. First you should know that 'PST timezone is 8 hours behind UTC timezone so for instance Jan 1st 2014, 4:30 PM PST (Wed, 01 Jan 2014 16:00:30 -0800) is equivalent to Jan 2nd 2014, 00:30 AM UTC (Thu, 02 Jan 2014 00:00:30 +0000). - The value for the field. 18. ; delimiter_text (required): Text representing the delimiter to split by. However, you can set the time portion of a timestamp, dropping the date portion entirely with date_trunc. edited Aug 18, 2015 at 10:57. 9999" turns to "2022-06-18 00:00:00" the same time date_trunc ('second', column) returns "2022-06-17 23:59:59". create function end_of_month(date) returns date as $$ select (date_trunc('month', $1) + interval '1 month' - interval '1 day')::date; $$ language 'sql' immutable strict; EDIT Postgres 11+ Pulling this out of the comments from @Gabriel , you can now combine interval expressions in one interval (which makes things a little shorter): However, date_trunc('day', created) is not equivalent to the other expressions, because it returns a timestamp value, not a date. In this case, it is used to truncate the result of the subtraction operation to seconds. date_trunc('field', source) source is a value expression of type timestamp (values of type date and time are cast automatically). I have a date field in a postgresql database (field name is input) how can I extract the month only from the date field? I used the syntax below, but I want it to show the actual month name, not a numeric value for the month. MySQL- Truncating Date-Time in a query. Truncation means setting specific parts of the date or time to zero or a default value while keeping the more significant parts unchanged. g. I tried date_trunc which does not have the precision I need. milliseconds. As shown in the results, the hours and above are preserved, while the minutes and seconds is truncated. Ask Question Asked 10 years, 9 months ago. If we want to look at order growth month over month, we’d use a truncation function in Postgres: #Truncate date specificity SELECT DATE_TRUNC(order_time, ‘month’), COUNT(*) as count_orders FROM orders GROUP BY 1 ORDER BY 1 DESC The DATE_TRUNC() function grabs the month and year from the date so you can get a. Alternatively you can use the date_trunc function: SELECT date_trunc ('day', my_date) Share. date) AND DATE_TRUNC ('day', c. Alternatively, create a function in postgres date_trunc_day(timestamp) that calls date_trunc('day', timestamp) and call the new function instead. 9. (Values of type date and time are cast automatically to timestamp or interval, respectively. However, Postgres' date type doesdate_trunc ( text, timestamp) → timestamp. 4. 2. When storing a date value, PostgreSQL uses the yyyy-mm-dd format e. CURRENT_DATE: DATE: Return the current date: CURRENT_TIME: TIMESTAMPTZ: Return the current time: CURRENT_TIMESTAMP: TIMESTAMPTZ: Return the current date and time with time zone at which the current transaction starts: DATE_PART: DOUBLE PRECISION: Get a field of a timestamp or an interval e. g. –How to perform date_trunc query in Postgres using SQLAlchemy. 4. SELECT date_trunc('day', CURRENT_TIMESTAMP), '2017-04-14 00:00:00';. g. In this case we have chosen to reduce the timestamp to full days:. You can however add an interval to a timestamp to receive a new timestamp. , year, month, week from a date or time value. PostgreSQL: Documentation: 9. 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. PostgreSQL - DATE/TIME Functions and Operators. The basic syntax of the DATE_TRUNC function is as shown below: DATE_TRUNC(precision, source);. 10. Delaying Execution. This uses PostgreSQL’s date_trunc () function, along with some date arithmetic to return the results we want. Users can add new types to PostgreSQL using the CREATE TYPE command. 4. 7) PostgreSQL Now (): Display without milliseconds. Also, you need to study the week in snowflake. date_trunc （ week 部分付き） 入力週を切り捨てて月曜日に開始します。 入力週を切り捨てて、定義された週の最初の日に開始します。 last_day （ week 部分付き） 入力週の日曜日を返します。 定義された週の最初の日からの相対的な入力週の最終日を返します。The DATE_TRUNC() method. to_char and all of the formatting functions let you query time however you want. The real usefu. 1994-10-27. ). DATE_TRUNC ('month','2020-09-12 15:23:00+05:45') gives 2020-09-01 05:45:00+05:45. For the date_part and date_trunc functions, arguments can be `year', `month', `day', `hour', `minute', and `second', as well as the more specialized quantities `decade', `century', `millenium', `millisecond', and. with ats (old_tz) as (select now() ) select old_tz, '2015-12-31'::timestamptz + (old_tz - date_trunc('day', old_tz)) new_tz from ats; OOPS. How to DATE_TRUNC by 10 days. RTRIM. The date_trunc function uses field either millisecond or second, but millisecond is too small for me and second too large. My SQL is: SELECT date_trunc('week', '2020-06-01'::timestamp)::date ||'-'|| (date_trunc('week', '2020-06-01'::timestamp)+ '6 days'::interval)::date; However, using. - It accepts two arguments, a datePart, and a field. It’s absolutely on target. 1, PostgreSQL 9. 次のように実例を示すとわかりやすいです。. 2. date_trunc ('day', yourtimestamp) will return a timesamp, but with hours, mins and secs to zero. In PostgreSQL, DATE_TRUNC() is a built-in date function that truncates/trims the unnecessary part from the date/time. 基本的な使い方を見ていこう。. (Values of type date and time are cast. 32 shows the available functions for date/time value processing, with details appearing in the following subsections. date_trunc ('day', now ())の落とし穴. date_trunc('month', current_timestamp) gives you the start of "this month" so in March this would be 2021-03-1 as the comparison for the upper limit is done using < it will include everything on the last day of February. 0 did not follow the conventional numbering of centuries, but just returned the year field divided by 100. So instead of having. Delaying Execution. 5. Thanks again! 👍 1. But I found that there's a trunc() function in pg_catalog. postgresql ignore milliseconds from timestamp when doing a select statement. The PostgreSQL TRUNC() function returns a number truncated to a whole number or truncated to the specified decimal places. My current work around is to map date_trunc as a function and explicitly call it but it seems odd to have to do that. A more specific answer is: where generated_time >= date_trunc ('hour', current_timestamp) and generated_time < date_trunc ('hour', current_timestamp) + interval '1 hour'. Table 9. You want to use the count aggregate as a window function, eg count (id) over (partition by event_date rows 3 preceeding). For partition naming you could use year and week number in the year YYWW:. with ats (old_tz) as (select now() ) select old_tz, '2015-12-31'::timestamptz + (old_tz - date_trunc('day', old_tz)) new_tz from ats; OOPS. 0 did not follow the conventional numbering of centuries, but just returned the year field divided by 100. , week, year, day, etc. The below will index but returns with timestamp added to date which. DATE_PART () is a built-in function in PostgreSQL that is used to extract/retrieve a specific part (like a month, year, hour, minutes, etc. EDIT: Perhaps the better solution for these two databases is: select cast (created_at as date)This worked perfectly! Would be really nice to have as a first class citizen in EF. Note that the specifier is a string and needs to be enclosed in quotes. The. SELECT EXTRACT(EPOCH FROM TIMESTAMP '2011-05-17 10:40:28. createQuery. The following table lists the behaviors of the basic arithmetic operators −. Syntax: date_trunc (text, timestamp) Return Type: timestamp. It's not immutable because it depends on the sessions time zone setting. 300 and 19:28:00. Use the date_trunc method to truncate off the day (or whatever else you want, e. Note that the specifier is a string and needs to be enclosed in quotes. It takes a date part (like a decade, year, month, etc. What is better: select date with trunc date or between. SELECT * FROM. 1) below the day precision (first parameter) the time zone offset of the result is always the same as the second parameters' offset. I am using Datagrip for Postgresql. extract will interpret such a time stamp in your current time zone (it does not know about the second. If you're certain that column should always store only the first of a month, you should also use a CHECK constraint. If you want to take the current date as the first argument, you can use the following form of the AGE() function: AGE(timestamp); Code language: SQL (Structured Query Language) (sql) For example, if someone has a birth date2000-01-01 and the current date is 2017-03-20, his/her age will be:We are using date_trunc, group by, and aggregate functions to retrieve table data as per day basis in PostgreSQL, we are using date_trunc function on the column from which we are retrieving data as per day basis. Sorted by: 89. This is not in any of other answers, which suggest to_char() and date_trunc(). 2014-05-09 16:03:51 will be returned as 2014-05-01 00:00:00. when querying the data, explain shows that all partitions are being queried when I'm constructing a date with date functions, whereas when I use hard coded dates only the targeted partitions are being scanned. Truncation means setting specific parts of. Four star feature compatibility Four star automation level Data Types PostgreSQL is using different function names. 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 ). SELECT SUM(rpt_unique_clicks) FROM reports WHERE rpt_datetime >= date_trunc('day', current_timestamp); On contrary, above query runs at least 15 seconds. PostgreSQL Version: 15 . 2: date_trunc('hour', timestamp '2001-02-16 20:38:40'). So using date_trunc('week',now())-'1 s'::interval; on the right side of your date operator should work. Table 8. Had been trying to figure out a select query to display days of week such as Monday, Tuesday, Wednesday, etc. If so, use date_trunc(): select date_trunc('month', order_date) as yyyymm If you really want a string, you should accept Nick's answer. Read: Postgresql date_trunc function Postgresql date add year. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. to the beginning of the month, year or hour. PostgreSQL specify that. Syntax: DATE_PART (field, source) In the above syntax the field is an identifier that is used to set the field to extract the data from the source. Truncate to specified precision; see Section 9. My Postgres version: "PostgreSQL 9. For formatting functions, refer to Section 9. Practical examples would include analyzing company’s quarterly. *, (first_week + ( (date - first_week::date) / 14)*14 * interval '1 day')::date as biweek from (select t. 372486-05'::timestamp with time zone); date_trunc ----- 2016-01-01 00:00:00-06 There is no such behavior when truncating to for example day: Introduction to the PostgreSQL DATE_PART function. century. 3. 9. l_date is the column where I would pull the date from. "GROUP BY date_trunc also? @Bravo: yes you need to repeat the expression in the group by clause. date_trunc関数. Neither of those expressions will make use of an index on created - you would need to create an expression based index with the expression used. 1 Answer. select cast (date_trunc ('month', current_date) as date) 2013-08-01. 4. PostGreSQL : date_trunc() returns timestamp with timezone when used on date. Syntax. or you can create your own. This query ran fine previously and on an interesting note, if I change the DB to Postgres 12, 13 or 14 the query also executes as expected. That truncates the date according to the timezone of the (Grafana) client resp. 10. Trunc date field in mysql like Oracle. Args:. 9. 3 Answers. - It retrieves the trimmed part with a specific precision level. "employees" AS "Employee" WHERE ("Employee". Next. Table 9-27 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. The day (of the month) field (1 - 31). Fully managed, PostgreSQL-compatible database for enterprise workloads. date_trunc. when the employee stopped doing that job) and the column start_date (when the employee started that job). Use the PostgreSQL AGE () function to retrieve the interval between two timestamps or dates. You can use this for PostgreSQL. , year, month, day, etc. 11. This list of the. postgres sql, date_trunc without extra zeroes. Finding the last date of the previous quarter from current date in PostgreSQL. So current_date - 1 would be enough. The DATE_TRUNC() function will truncate timestamp or interval data types to return a timestamp or interval at a specified precision. Is there a way I could update based on a date range in a postgres DB? Meaning if I have a row with following values, name code some_timestamp abc 1 2020-09-07T13:22:23. 2. Take a look at AT TIME ZONE described just below date_trunc in the link above, you could use something like. PostgreSQL 8. dateoftransfer::date)::Date from table_withdates; --returns 2005-10-01. Looks like I could go your way or just go full native query instead. update foo set created_at = date_trunc('second', created_at) where created_at is not null; Instead of using date_trunc you can also just cast the value: created_at::timestamp(0) for the update statement, or current_timestamp::timestamp(0) in the default value. Issue in creating a function in PostgreSQL using date_trunc. . The query looks like this: SELECT COUNT (*), EXTRACT (HOUR FROM paid_at) AS HOUR FROM transactions WHERE paid_at >= '2015-01-01 00:00:00' AND paid_at <= '2015-01-31. We are also looking at upgrading to a newer version of Postgres but that is further out. Syntax: date_trunc(text, timestamp) Return Type: timestamp. e. Postgresql date to string format. SELECT date_trunc ('month', CURRENT_DATE); Last day isn't much more difficult either. 29 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. The date part to which to truncate the timestamp value. Truncate to specified precision; see Section 9. So using date_trunc('week',now())-'1 s'::interval; on the right side of your date operator should work. 2: date_trunc('hour', timestamp '2001-02-16 20:38:40') 2001-02-16 20:00:00:. I'm trying to create quarterly average for player scores, however the default behaviour of postgres date_trunc('quarter', source) is that it starts first quarter with YYYY-01-01. Need group data by each line time interval, e. The range of values for date values in PostgreSQL is 4713 BC to 5874897 AD. And best solution is 1st that suggested by marco-mariani. g. An alternative pproach is to use to_char function. Assuming you are using Postgres, you need quotes around your date constant and can convert to the right types: WHERE job_date >= DATE_TRUNC('month'::text, '2019. This function with datetime or string argument is deprecated, use DATE_TRUNC instead. 0. 0. When dealing with dates, it accepts as a parameter a Template Pattern for Date/Time (see link above) then a timestamp, and returns a timestamp. syntax: CAST (date AS datatype) Where, date: It is the date that we want to convert into a string and it can be any literal or an expression that evaluates to date value. 1. Table 9. PostgreSQL provides a large number of functions and operators for the built-in data types. date dollars 2016-10-03 1 2016-10-05 1 2016-10-10 1 2016-10-17 2 2016-10-24 2 date_trunc PostgreSQL function equal for mySQL. Jun 2 at 11:46. Below is the example, and the syntax of the date_trunc function is as follows. I have a slow query that generates a report of account activity per week over the past year. POSTGRESQL Course Bundle - 5 Courses in 1 | 1 Mock Test. Q&A for work. I'm trying to create quarterly average for player scores, however the default behaviour of postgres date_trunc('quarter', source) is that it starts first quarter with YYYY-01-01. DATE_TRUNC. Evan Carroll. you need to qualify the field with the table name. Truncate to specified precision; see Section 9. g. Current Date/Time 9. 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. These SQL-standard functions all return values based on. I want something in between like 100 milliseconds (1/10 second). I'm able to recreate this issue in a new clean Docker-TimescaleDB-container (:latest-pg12), but not in an otherwise equivalent PostgreSQL-12. It is is IMMUTABLE (for timestamp without time zone). I see that date_trunc function returns timestamp and intervals cannot be cast to date type: select current_date -. The PostgreSQL TRUNC() function returns a number truncated to a whole number or truncated to the specified decimal places. Is that what you want? we are using Postgresql 9. - It accepts a “datePart” and a “field” as arguments. select count(*) as logged_users, EXTRACT(hour from login_time::timestamp) as Hour from loginhistory where login_time::date = '2021-04-21' group by Hour order by Hour;. Pad on the right of a string with a character to a certain length. CURRENT_DATE: DATE: Return the current date: CURRENT_TIME: TIMESTAMPTZ: Return the current time: CURRENT_TIMESTAMP: TIMESTAMPTZ: Return the current date and time with time zone at which the current transaction starts: DATE_PART: DOUBLE PRECISION: Get a field of a timestamp or an interval e. PostgreSQL's approach uses the month from the earlier of the. date, count (se. 2 do mention both forms though. In PostgreSQL, DATE_TRUNC Function is used to truncate a timestamp type or interval type with specific and high level of precision. created), 'YYYY-MM-DD')) GROUP BY d. But the start day is coming as Monday. TRUNC( date_value, format ) You are providing a string value instead of a date value and 'dd-mm-yy' is an invalid format (you just want to truncate to the start of the day using 'dd' as the format or the start of the month using 'mm' or the start of the year using 'yy' - but using all three together does not make. Asked 10 years, 9 months ago. AT TIME ZONE 9. and while the condition is > '2018-10-01' then all dates in the month October will not be shown in the result. id) FROM ( select to_char (date_trunc ('day', (current_date - offs)), 'YYYY-MM-DD') AS date FROM generate_series (0, 365, 1) AS offs ) d JOIN sharer_emailshare se ON (d. 这是 PostgreSQL date_trunc() 函数的语法： date_trunc ( field TEXT , source TIMESTAMP ) -> TIMESTAMP date_trunc ( field TEXT , source TIMESTAMPTZ , time_zone TEXT ) -> TIMESTAMPTZ date_trunc ( field TEXT , source INTERVAL ) -> INTERVAL In Postgresql, to truncate or extract the week of the timestamp value, pass the week as a string to the date_trunc function. For now, I do a workaround using time_bucket('1 day', timestamp) or include it as part of CTE / with, from which I will call the on date_trunc('month', time_bucketed_day_column). Use the DATE_TRUNC() function if you want to retrieve a date or time with a specific precision from a PostgreSQL database. e. Functions but this works for my case. – zhrist. For common time intervals built into date_trunc() (like 1 hour and 1 day in your examples) you can use a shortcut. A primer on working with time in Postgres. Pictorial Presentation of PostgreSQL DATE_TRUNC() function. *, min (date_trunc ('week', date)) over () as first_week from t ) t; Here is a db<>fiddle. Current Date/Time. SELECT * FROM table WHERE DATE_TRUNC('day', date ) >= Start Date AND DATE_TRUNC('day', date ) <= End Date Now this solution took : 1. 4. answered Aug 18, 2015 at 10:52. Trimming trailing :00 from output after date_trunc. The subtraction of timestamps yields an interval. If it doesn't work I might try what you said i. CREATE INDEX ON. (Values of type date and time are cast automatically to timestamp or interval, respectively. g. SELECT TO_CHAR(timestamp_column, 'YYYY-MM-DD HH24:MI') AS formatted_ts FROM table_name;. . It takes a date part (like a decade, year, month, etc. Learn how to round or truncate timestamps in PostgreSQL for effective time-based grouping using the date_trunc function. PostgreSQL expected 1095 rows – and there are in fact 1096 rows. In postgres, you could phrase this as: date_trunc ('quarter', current_date) + interval '3 months' - interval '1 day'. What is the date_trunc Function? The date_trunc function is one of the best features available in the PostgreSQL database to deal with dates. toLocalDateTime () When you use date_trunc ('day', now () at time zone 'Asia/Tehran') (column tehran_local_start_of_today) it indicates the start of today in Tehran local. Hot Network QuestionsFirst day is easy. timestamp '2001-09-29 03:00' - timestamp '2001-09-27 12:00'. 2020-04-01, and has the advantage that subsequent steps in the pipeline can read it like a normal date. 8. 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. 3. Consequently, the timestamp will be rounded/truncated based on the specified date field. I ended up with a select query displaying dates of a week, select ( (date_trunc ('week',current_date)::date) + (i+6)) as week_date from generate_Series (0,6) i; Is there a way to get the result as Monday, Tuesday and so on. See Postgres Date/Time Functions and Operators for more info In PostgreSQL, the DATE_TRUNC function is used to truncate a date, time, or timestamp value to a specified precision. I have to convert a postgres query to Sequelize query. You see the last two colums being blank, date_trunc returns null. l_date is the column where I would pull the date from. 0 did not follow the conventional numbering of millennia, but just returned the year field divided by 1000. Stack Overflow. Table 9-28 shows the available functions for date/time value processing, with details appearing in the following subsections. How to use the date_trunc function for biweekly grouping. , year, month, day, etc. Let’s add a year to any date. date_trunc. This gives the date rounded to the start of the quarter, e. date_trunc still gives me the whole date. Oct 27, 2013 at 12:41. end_date) >= DATE_TRUNC ('day', q. date_trunc ('hour', created) + extract (minute from created)::int / 15 * interval '15' minute. 说明：DATE_TRUNC 函数根据您指定的日期部分（如小时、周或月）截断时间戳表达式或文本。DATE_TRUNC 返回指定的年的第一天、指定的月的第一天或指定的周的星期一。. PostgreSQL cung cấp một số hàm trả về giá trị liên quan đến ngày giờ hiện tại. 「今日の日付（今日の0時）がほしいんだけど、、、」と思ったときにしょうもない落とし穴にハマってしまったので、. 0. It can also truncate the value to a specified precision in a specified time zone. 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. For example I need to get number of sales each week. js or if node. Recently, I have been getting familiar with PostgreSQL(using 8. For example, "2022-06-17 23:59:59. demo:db<>fiddle. Ask Question Asked 11 years, 7 months ago. Note: All the date field parts other than the targeted. Is that what you want?The date_trunc(text, timestamptz) variant seems a bit under-documented, so here are my findings:. . 7. Postgresql date_trunc function. The DATE_PART() function extracts a subfield from a date or time value. 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. Using column::timestampt (0) may lead to unexpected rounding up column value. Truncate date in units other than default choices using date_trunc (Postgres 9. 2 Answers. Let’s see the following example. Getting results between two dates in PostgreSQL. 24. It will not convert the value to a date. 6. user330315. 2014-05-09 16:03:51 will be returned as 2014-05-01 00:00:00. select date_trunc ('day', e. AT TIME ZONE. date_trunc(field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. If you want both quarter and year you can use date_trunc: SELECT date_trunc ('quarter', published_date) AS quarter.