Rabbit. The DATE_PART() function extracts a subfield from a date or time value. postgresql error: function date_trunc(unknown, text) does not exist LINE 1: SELECT DATE_TRUNC('day', "Date") AS __timestamp, ^ HINT: No function matches the given name and argument types. That is the query for Q1: select '2020_Q1' as time_frame, id, status, date, agent, country, sale from sales where date >= '2020-01-01' and date < '2020-03-31'Introduction. for example 2018-10-15 will be 2018-10-01 and 2018-10-30 also will be 2018-10-01. Sorted by: 2. note: similar question as DATE lookup table (1990/01/01:2041/12/31). (2) as CONCAT_WS appears to require text, not numeric input, you may have to do something like mutate (the_year = as. source must be a value expression of type timestamp, time, or interval. Formats timestamp as a string using format. 1) precision The precision argument specifies fractional seconds precision of the second. 'QUARTER': truncate to the first date of the quarter. SELECT date_trunc ('hour', date1) AS hour_stump , (extract (minute FROM date1)::int / 5) AS min5_slot , count (*) FROM table1 GROUP BY 1, 2 ORDER BY 1, 2; You could GROUP BY two columns: a timestamp truncated to the hour and a 5-minute-slot. 9. if you want timestamp instead of timestamptz cast the date to timestamp first. SELECT date_trunc ('month', cast (my_date as timestamp)) FROM my_table. Showing an example based on the output you've outlined. Basically, there are two parameters we. It's best explained by example: date_trunc('hour',TIMESTAMP '2001-02. To have one row per minute, even when there's no data, you'll want to use generate _ series. Table 9. 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. edited Aug 18, 2015 at 10:57. the Use of the DATE_TRUNC() Function in PostgreSQL. Add a comment. I have tried using something like: SELECT DATE_TRUNC('quarter', TIMESTAMP '20200430 04:05:06. date_trunc | 2020-07-01 03:00:00+10 date_trunc | 2020-07-01 02:00:00+10 The local timezone when I ran these examples was Australia/Brisbane. 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. The trunc () function is a mathematical function present in PostgreSQL. Table 9. Pad on the right of a string with a character to a certain length. dim_time__month_start_date date NOT NULL, dim_time__week_start_date date NOT NULL, dim_time__quarter_start_date date NOT NULL, dim_time__year_start_date date NOT NULL, The redundant columns wouldn't even help performance of the query at hand. From the documentation: date_part (): The date_part function is modeled on the traditional Ingres equivalent to the SQL-standard function extract: 2. DATE 'YYYY- [M]M- [D]D'. 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. When storing a date value, PostgreSQL uses the yyyy-mm-dd format e. Follow. 2017-05-14 20:38:40. --set the first day of the. (Expressions of type date will be cast to timestamp and can therefore be used as well. Use the date_trunc () function to get the first day of the quarter and then subtract one day. Group by Year. But the start day is coming as Monday. 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. The extract function is primarily intended for computational processing. 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. Here’s a bit of code adapted from the PostgreSQL wiki that I like for creating the ever necessary date dimension in PostgreSQL. Here’s the current timestamp. Ex:If I have 2010-01-01, I would like to return 2010-03-31, and so on. This function is most widely used for creating time series and aggregating at a granular level. in general, in group by queries, does it matter whether using - functions on the date - a day table that has extraction pre-calculated. 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. . 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. Right now the cod. I have a table where date | interval juin 1, 2022, 12:00 AM | 0 years 0 mons 0 days 0 hours 1 mins 58. PostgreSQL provides a number of functions that return values related to the current date and time. The following bug has been logged online: Bug reference: 2664 Logged by: Yoshihisa Nakano Email address: nakano. 1. ) field selects to which precision to truncate the input value. Truncating any date or timestamp to the month level will give you the first of the month containing that date. The function date_trunc is conceptually similar to the trunc function for numbers. But, 'quarter' is invalid for interval. SELECT date_trunc. A date value represents a logical calendar date (year, month, day) independent of time zone. 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. Example 1: Truncate a DATE value to the beginning of the month. g. (Expressions of type date will be cast to timestamp and can therefore be used as well. 9. 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。. 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. many queries are by week, month or quarter when the base table date is either date or timestamp. What I need is to "round down" the month to day one, and I. 29 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. 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. Any valid year (e. SELECT * FROM generate_series (date_trunc ('quarter', '2008-02-01 00:00'), '2009-01-01 12:00', '3 months'); – Jason Green. A primer on working with time in Postgres. 32 shows the available functions for date/time value processing, with details appearing in the following subsections. We had discussed about the Date/Time data types in the chapter Data Types. g. 1. All months in a year: SELECT ADD_MONTHS (TRUNC (SYSDATE, 'yyyy'), LEVEL - 1) m FROM DUAL CONNECT BY. WHERE date_survey >= date_trunc('year', now()); Or maybe add EXTRACT('quarter' FROM date_survey) AS start_season to add the quarter number. The SELECT statement below extracts the quarter each date_renting falls in. First, we have the date part specifier (in our example, 'month'). 1 Share Follow 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 Server. ). 2 Answers. AT TIME ZONE. Its type is timestamp without time zone. date 、 time 、または timestamp を指定された精度に切り捨てます。. date_trunc('field', source) source is a value expression of type timestamp (values of type date and time are cast automatically). (Values of type date and time are cast. You can readily convert them to the format you want, get the difference between two values, and so on. Part of AWS Collective. The DATE_PART () function extracts a subfield from a date or time value. The snippet provided below shows how to use the DATE_TRUNC () function in Postgres: DATE_TRUNC (dateField, timestamp); Specify the date field, such as year, month, day, etc. For formatting functions, refer to Section 9. date, q2. The full-list is available in the Postgres docs. and while the condition is > '2018-10-01' then all dates in the month October will not be shown in the result. extract() complies with the SQL standard, date_part() is a Postgres specific query. CREATE. Right now the cod. Syntax. date_created)::date, 'Month YYYY') as "Month / Year", count (distinct l. Note that truncation is not the same as extraction. date_trunc will truncate a date or timestamp to the specified date/time part. The PostgreSQL date_part function extracts parts from a date. DATE_DIFF. day::date FROM generate_series (timestamp '2004-03-07' , timestamp '2004-08-16' , interval '1 day') AS t (day); Additional date_trunc () is not needed. It's best explained by example: date_trunc('hour',TIMESTAMP '2001-02. Sorted by: 3. Postgres has plenty of date-specific functions -- from date_trunc() to age() to + interval-- to support dates. - It accepts a “datePart” and a “field” as arguments. . Split a string on a specified delimiter and return nth substring. This uses PostgreSQL’s date_trunc () function, along with some date arithmetic to return the results we want. AT TIME ZONE. For formatting functions, refer to Section 9. Format date with to_char; Setup. Here is how you can convert an epoch value back to a time stamp: SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second'; hour. This is not by any means an exhaustive guide to date and time expressions in BigQuery. ) field is an identifier or string that selects what field to. Table 9. RPAD (‘ABC’, 6, ‘xo’) ‘ABCxox’. Subtracts a specified time interval from a DATE value. Apr 20, 2017 at 8:39. The function date_trunc is conceptually similar to the trunc function for numbers. select cast (date_trunc ('month', current_date) as date) 2013-08-01. Summary: this tutorial shows you how to use the PostgreSQL date_trunc() function to truncate a timestamp or interval to a specified level of precision. 5. 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. I would suggest not thinking too hard about the problem and just using the first date/time of the month. 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. For formatting functions, refer to Section 9. Example 3:. dataset. 9. Sorted by: 2. CREATE INDEX ON. Connect and share knowledge within a single location that is structured and easy to search. Realizing this is an old answer, but I recently ran into this. Postgres quarter function. SELECT CASE WHEN created_at BETWEEN date_trunc. 30 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. It also uses this format for inserting data into a date. The TRUNC() function accepts two arguments:. 2017) YEAROFWEEKISO. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. PostgreSQL provides a number of functions that return values related to the current date and time. 3. g. 9. 9. WW truncates date to the nearest previous day same to the first day of week of the year. ) field is an identifier or string that selects what field to. answered Aug 18, 2015 at 10:52. Follow. 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 transactions in PostgreSQL 9 that happened earlier than the end of the last week. Remove the longest string that contains specified characters from the right of the input string. If the contraint should apply to the tservice as type "date" you might as well create the tservice column as type "date" instead. The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. For example: Truncating a timestamp down to the quarter returns the timestamp corresponding to midnight of the first day of the quarter for the input timestamp. To represent an absolute point in time, use a timestamp instead. 1. 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. 1 20210206, 64-bit. Note that to_date () returns a date so your code would remove the just added time part again. PostgreSQL provides a number of functions that return values related to the current date and time. Also, we can calculate time intervals using these functions that will help us. 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 date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. 4. column. date_trunc always returns a timestamp, not a date. , “Year” in the above example) to their initials. I think the :: operator is more common in "Postgres land". ). "W" = week of month (1-5) (the first week starts on the first day of the month) So if the month starts on Friday, the next Thursday will still be week 1, and the next Friday will be the first day of week 2. Postgres examples include comparing years, quarters, day of week and rolling time periods. Section 9. When storing a date value, PostgreSQL uses the yyyy-mm-dd format e. The function date_trunc is conceptually similar to the trunc function for numbers. 001 WHEN 'second' THEN 1. Here is my sql below (This is based on Postgres. Table 9. date_trunc¶. or you can create your own. Note that to_date () returns a date so your code would remove the just added time part again. table` GROUP BY ddateTruncates a TIMESTAMP and returns a DATE. 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. 8. Be aware of corner case pitfalls with type timestamp (or date ) depending on the current time zone setting (as opposed to timestamptz ). This query compares revenue per quarter for 2018. select date_trunc ('minute', created_at), -- or hour, day, week, month, year count(1) from users group by 1. This query is working for me to give me the running total of total IDs by week. Almost as it can't take any interval with units of months or more (due to varying duration). It is only meant as a quick reference to those I use most often. 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. 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. ) Details: 'quarter' is not mentioned in the doc as valid fields for date_trunc(). A weird way to number weeks but might be what the OP is after :) – Andomar. 6. 9. This example uses TRUNC on a date to truncate it into a month. The range of values for date values in PostgreSQL is 4713 BC to 5874897 AD. Share. In Postgresql, we can also add a year to the current date using the INTERVAL data type. Assuming data type timestamp. These SQL-standard functions all return values. 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. quarter. PostgreSQL での DATE_TRUNC () 関数の使用. 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. Sorted by: 3. date=to_char (date_trunc ('day', se. 'QUARTER' First day of its quarter. Assuming you want all "overlapping" time periods, i. 1+) that I've overlooked. The SELECT statement below extracts the quarter each. 2) at or above day precision, the time zone offset is recalculated, according to the current TimeZone configuration. 2. For formatting functions, refer to Section 9. Date_selector >) AS ddate, SUM (value1) AS value1FROM `project. Postgres Pro provides a number of functions that return values related to the current date and time. DATE_TRUNC is very handy for aggregating your data by a particular date_part, like MONTH. (Values of type date and time are cast automatically to timestamp or. To store date values, you use the PostgreSQL DATE data type. Sorted by: 2. The problem with the selected solution is that make the month configurable so that the quarter can start at any month is not possible; you have to change the query to change the starting month. In order to group our orders by month, in PostgreSQL we'll use the date_trunc built-in function. For example: SELECT DATE_TRUNC ('year', date) AS year, SUM (quantity) FROM sales GROUP BY year; This query will return a list of years along with the total quantity sold each year. Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to. ·. date_trunc (field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. region, q1. . Current Date/Time. These SQL-standard functions all return values based on the start time of the current. Date/Time Functions and Operators. create table foo ( first_of_month date not null check (extract (day from first_of_month) = 1) ); insert into foo (first_of_month) values ('2015-01-01. A similar functionality provides the Oracle compatible function TRUNC [ATE] (datetime). 32 shows the available functions for date/time value processing, with details appearing in the following subsections. 1. 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. sql. SELECT date_trunc($1, purchase_date) unit_of_time, SUM(total) FROM orders WHERE purchase_date >= $2 AND purchase_date <= $3 GROUP BY unit_of_time ORDER BY unit_time; [interval, startDate, endDate] The above query works correctly for when I pass in either 'month' or 'day' as the interval variable, but gives incorrect values. (Values of type date and time are cast automatically to timestamp or interval, respectively. Like for example, I passed a date as on 12th January, 2015, I need the result to be as 4th quarter of 2014. select cast (date_trunc ('month', current_date) as date) 2013-08-01. 切り捨ては抽出とは異なります。例： タイムスタンプを四半期まで切り捨てると、入力タイムスタンプの四半期の最初の日の真夜中に対応するタイムスタンプが返されます。The PostgreSQL DATE_TRUNC function is used to truncate the date and time values to a specific precision (into a whole value), such as 'year', 'month', 'day', 'hour', 'minute', or 'second', in a string format. The subtraction of timestamps yields an interval. 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. 9. 9. WHERE date_survey >= date_trunc('year', now()); Or maybe add EXTRACT('quarter' FROM date_survey) AS start_season to add the quarter number. AT TIME ZONE. The quarter of the year (1–4) that the date is in. shahkalpesh. These SQL-standard functions all return values based on the start. The PostgreSQL function you need here is date_trunc. date_trunc ( field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. See below. 参数 field. 11. 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. Covers all your examples. 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. 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). 8. 9. age; current_date; current_time; current_timestamp; date_part; extract; localtime;. ). Most texts you’ll find online will tell you that partitioning is done by executing x and y, end of story. Example of the possible combinations below: Interval. 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. Table 9. 9. date, count (se. These queries work fine in oracle but am in the process of converting it to a postgres query but it complains. dataset. 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. ). 2. 9. 1 Answer. From what I'm reading, you're looking for the first and last stored day of the week, so: WITH first_stored AS (SELECT min (stored_date) as first FROM stored WHERE stored_date > DATE_TRUNC ('WEEK', NOW ()) - INTERVAL '8 DAY'), last_stored AS (SELECT max (stored_date) as last FROM stored WHERE. 9. I need it to return april 22. g. TRUNC(timestamp) Arguments. id, generate_series(well_schedules. This is a timestamp with time zone value which refers in fact to 23:59:59 on sunday, but with 2 hours of difference with UTC time, depends on your locale and settings. 000001 WHEN 'millisecond' THEN 0. These SQL-standard functions all return. 9. 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. These SQL-standard functions all return. -- date_trunc（日付の切り捨て）の構文 date_trunc( 精度 , 日付・時刻 ); 精度には'year'、'month'、'day'等を指定します。. DATE_TRUNC. Example 2: Truncate a TIMESTAMP value to the beginning of the hour. appointment_date::date + appointment_end_time::time. The date is complete (year, month, and day). 4. The week number will be in the range of 1 to 53, depending on the specific date and the datestyle setting in PostgreSQL. Use the aggregate FILTER clause in Postgres 9. The date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. ) field selects to which precision to truncate the input value. Table 9. The Oracle code that I posted returns april 22, so I need postgres to do the same. The following example shows how to use the date_trunc () function to truncate a timestamp value to hour part, as follows: SELECT date_trunc('hour', TIMESTAMP '2022-05-16 12:41:13. Current Date/Time. We are also looking at upgrading to a newer version of Postgres but that is further out. 1994-10-27. The functions in this section use a format string that is compatible with JodaTime’s DateTimeFormat pattern format. Nice. You can then add more conditions to the CASE/WHEN for additional quarters. values date_trunc ('MONTH', DATE ('2007-02-18')) Result: 2007-02-01 00:00:00. date_dim_id INT NOT NULL, date_actual DATE NOT NULL, epoch BIGINT NOT NULL, day_suffix VARCHAR(4) NOT NULL, day_name. g. Current Date/Time. amount), DATE_TRUNC('quarter', orders. I am just highlighting the date modification part) ## 6 days interval "date_trunc ('month', created_at) + (date_part ('day', created_at)::int - 1) / 6 * interval '6 day'" ## 10 min interval "date_trunc ('hour', created_at) + date_part ('minute', created_at)::int / 10 * interval '10 min'". However, date_trunc('day', created) is not equivalent to the other expressions, because it returns a timestamp value, not a date. I am thinking of defining variables with reference to current date. 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. g. 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. 8. CREATE OR REPLACE FUNCTION last_day(date) RETURNS date AS $$ SELECT (date_trunc('MONTH', $1) + INTERVAL. 33. I am converting a postgres app to an Oracle app. g. Practical examples would include analyzing company’s quarterly. SPLIT_PART. Everything to the “right” of the datepart you selected will be “blank” or go back to the beginning (in other words, if you truncate your query at year, then the month, day and time will “reset” to 01-01 00:00). Let's see: = $ SELECT date_bin ('5 minutes', now ()); ERROR: FUNCTION date_bin (UNKNOWN, TIMESTAMP WITH TIME zone) does NOT exist. Table 9. Postgres has lots of functions for interval and overlap so you can look at data that intersects. I've looked around and I can't figure out the right syntax for accessing the month and comparing with the current month. 16. quarter: Quarter (1 to 4) second: Seconds (and fractional. Sorted by: 3. Let’s add a year to any date. js ORM for postgreSQL), im trying to group by date range, and keep a count of how many items where in that table. To verify that, connect to PostgreSQL with psql and run dx to list the extensions. 9. I'm making my first laravel project, using postgres, and I'd like to be able to access all the people with a birthday this month (my people table has a birthdate field that's a date). In PostgreSQL, various inbuilt functions like DATE_PART(), EXTRACT(), and DATE_TRUNC() are used with the GROUP BY clause to group the table’s data by a specific date field. Explore options like 'second', 'minute', 'hour', 'day', or 'month' to tailor your data analysis. 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);. The DATE type in PostgreSQL can store a date without an associated time value: PostgreSQL uses 4 bytes to store a date value. The function date_trunc is conceptually similar to the trunc function for numbers. Oracle has the trunc function and PostgreSQL / Redshift have the date_trunc function that allows you to truncate a timestamp to a specific unit of measure like year, quarter, month, week, etc. SELECT my_date::date::timestamp. PostgreSQL date_part function will allow retrieving subfields from the date and time value, e. , ‘year’, ‘quarter’, ‘month’, ‘day’, ‘hour’, ‘minute’, ‘second’, etc. Then format date the way you want. date_trunc ( field, source [, time_zone ]) source is a value expression of type timestamp, timestamp with time zone, or interval. Then, removing a day will give you the date of the last day of the month of the provided date. g. The syntax of the LOCALTIME function is as follows:. The quarter of the year (1 - 4) that the day is in. date_trunc('hour', interval '2 days 3 hours 40 minutes') 2 days 03:00:00:. md","path":"README. g. You would need to use to_timestamp () if you really want. 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. 29 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. 5. The image you added to the question suggests that the function is in pg_catalog, but the extension is. timestamp)) from rollup_days as rp; To convert the timestamp back to a bigint, use extract ()Use the date_trunc method to truncate off the day (or whatever else you want, e. The date_trunc function in redshift is specifically used to truncate the specified precision. 6. For more information, see TRUNC function. Use the DATE_TRUNC() function if you want to retrieve a date or time with a specific precision from a PostgreSQL database. Group by on Postgresql Date Time. SELECT date_trunc. 5. shahkalpesh. date_trunc() also accepts other values, for instance quarter, year etc. PostgreSQL provides a number of functions that return values related to the current date and time. PostgreSQL provides a number of functions that return values related to the current date and time. I have this problem. Interprets an INT64 expression as the number of days since 1970-01-01. You can also add the full timezone name as a third argument. 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. Notes. 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. SELECT EXTRACT (EPOCH FROM TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-08'); Result: 982384720 SELECT EXTRACT (EPOCH FROM INTERVAL '5 days 3 hours'); Result: 442800.