Thanks, i will consider it!Date: 20 July 2000, 05:00:19. Note that the latter returns a timestamp with time zone, not a timestamp value. Read: Postgresql date_trunc function Postgresql date add year. Functions but this works for my case. if you want timestamp instead of timestamptz cast the date to timestamp first. Follow answered Aug 28, 2015 at 6:57. 0. You may be misunderstanding what date_trunc does. PostgreSQL Date Part Hour From Interval. Special calculation is needed for week/quarter. 3 Answers. 3 . 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. 2. The date_trunc() function in PostgreSQL is used to truncate a timestamp or interval value to a specified unit. the_date 2000-12-31 00:00 Is there a way to tell date_trunc to do day/month/year conversions based on the timezone it is feeded with? The expected output would be: 2001-01-1 00:00+01009. How to use the date_trunc function for biweekly grouping. For formatting functions, refer to Section 9. Introduction to the PostgreSQL DATE_PART function. For this purpose, specify the “MONTH” as the first argument to any of the functions mentioned above and then use the GROUP BY clause. I just sent a note about that to the pgsql-docs mailing list so hopefully it will be fixed soon. With PostgreSQL there are a number of date/time functions available, see here. This worked perfectly! Would be really nice to have as a first class citizen in EF. To generate a series of dates this is the optimal way: SELECT t. Postgres has lots of functions for interval and overlap so you can look at data that intersects. Date_trunc is a function that returns a date part of a date or a time part of a time. To get the latest date per category and month, simply group by both. 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. SELECT TRUNC(CURRENT_TIMESTAMP) Postgresql. For example I need to get number of sales each week. How to perform date_trunc query in Postgres using SQLAlchemy. now (). 2 dea7d4996a What are you trying to achieve? Use Postgresql DATE_TRUNC() Function What happened? When I run the following query on Dbeaver or DataGrip, the result is like expected, but in Grafana, its subtracting -1 in the month and showling the last day otf the. Current Date/Time. 9. A DATE column does not have a format. I would like to change the date into month. beikov February 2, 2023, 2:29pm 4. You might need to add explicit type casts. Use the below command: SELECT date_trunc ('week', timestamp'2021-08-23 19:14:20'); Postgresql date_trunc week. PostgreSQL releases before 8. SELECT date_trunc('MONTH', dtCol)::date; But getting the last day is not so straight forward. This generates a timestamp value, that you can cast if you. 300 and 19:28:00. See the table of available functions for date/time value processing and the examples of date_trunc usage. PostgreSQL provides a number of functions that return values related to the current date and time. date) going over the date/time functions in. (Values of type date and time are cast automatically to timestamp or. DATE_TRUNC() is a function used to round or truncate a timestamp to the interval you need. Table 8-9. source is a value expression of type timestamp or interval. The DATE_PART() function extracts a subfield from a date or time value. Finding the last date of the previous quarter from current date in PostgreSQL. source is a value expression of type timestamp or interval. The basic syntax of the DATE_TRUNC function is as shown below: DATE_TRUNC(precision, source);. The real usefu. PostgreSQL provides a number of functions that return values related to the current date and time. PostgreSQL. PostgreSQL provides a number of functions that return values related to the current date and time. 9. answered Aug 18, 2015 at 10:52. 1+) that I've overlooked. Forgive me if I am oversimplifying your question, but wouldn't a simple cast and date_trunc do the trick? SELECT date_trunc('second','2022-06-15T08:27:00. Truncation means setting specific parts of the date or time to zero or a default value while keeping the more significant parts unchanged. and while the condition is > '2018-10-01' then all dates in the month October will not be shown in the result. g. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. Slobodan Pejic Slobodan Pejic. g. The below will index but returns with timestamp added to date which. 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. - It accepts two arguments, a datePart, and a field. , week, month, and year. You can use DateStyle to control how PostgreSQL emits dates, but it's global and a bit limited. 8. date_part(text, interval) double precision: 获取子域(等效于extract)； date_part('month', interval '2 years 3 months') 3: date_trunc(text, timestamp) timestamp: 截断成指定的精度； date_trunc('hour', timestamp '2001-02-16 20:38:40') 2001-02-16 20:00:00: date_trunc(text, interval) interval: 截取指定的精度，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. The syntax for the function is DATE_TRUNC('datepart', timestamp), seems you need to use as DATE_TRUNC('month', session_utc)(this already truncates to the first date of April 2019 i. But in the check constraints, I see that the truncated date is being shifted. Expected output format:EXTRACT関数 日付値から任意の日付要素を求める. ·. PostgreSQL Version: 9. The most convenient method to group table data is the DATE_TRUNC() function, which allows us to truncate a timestamp to a specific level of precision, such as the month, day, hour, etc. 29 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. I'm trying to create an index on the month and year of a date field (in 8. to the beginning of the month, year or hour. In Postgres, DATE_TRUNC () has the following intervals. date_trunc('month', CURRENT_DATE) does not return the month, it returns a complete timestamp at the. 1: Date/Time Types. Sorted by: 14. It can also return a number truncated to the whole number if no precision is defined. Also avoids misunderstandings general communication. 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 However, date_trunc('day', created) is not equivalent to the other expressions, because it returns a timestamp value, not a date. As one gets converted to the other, there is absolutely no performance difference. start_date) <= DATE_TRUNC ('day', q. The following code was working on Hibernate 5. 1. 16. In this case, it is used to truncate the result of the subtraction operation to seconds. For formatting functions, refer to Section 9. SELECT date_trunc ('month', cast (my_date as timestamp)) FROM my_table. date_trunc¶. The subquery is not strictly needed, but it makes the code easier to read. DATE_TRUNC truncates the Postgres timestamp to a specified precision. That is still a distinguishable value. Fiddle with your system until. This query works except it does not return records for the dates (time_added) that bx_broker doesn't have data: select bx_broker as Broker, date_trunc ('day', time_added) as date, avg (bx_avgpxvsarrival) as AvgPr_vs_Arrival, avg (bx_avgpxvsoppvwapbpsblackrockasia) as. A cast to timestamp (0) or timestamptz (0) rounds to full seconds: Fractions are not stored in table columns of this type. Share. Summary: in this tutorial, we will introduce you to the PostgreSQL DATE_PART() function that allows you to retrieve subfields e. Delaying Execution. date, count (se. 7. date_created) )AS DAY, this is my output 2013-02-04 00:00:00+00. It's best explained by example: date_trunc('hour',TIMESTAMP '2001-02. Recently, I have been getting familiar with PostgreSQL(using 8. This is an excerpt from my sql query. Share. 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. CREATE TABLE log ( log_id SERIAL PRIMARY KEY, message VARCHAR ( 255) NOT NULL , created_at TIME DEFAULT. 217k 25 25 gold badges 85 85 silver badges 136 136 bronze badges. Note that the specifier is a string and needs to be enclosed in quotes. For some formats, ordering of month, day, and year in date input is ambiguous and there is support for specifying the expected ordering of these fields. CURRENT_DATE関数 現在の日付を求める. These SQL-standard functions all return values based on. Q&A for work. date_trunc ( text, timestamp) → timestamp. On the other hand you can use date_trunc function. The function date_trunc is conceptually similar to the trunc function for numbers. created), 'YYYY-MM-DD')) GROUP BY d. century. 9. この. PostgreSQL provides a number of functions that return values related to the current date and time. PostgreSQL: Greatest will return the largest non-null expression, or null if all expressions are null. The function date_trunc is conceptually similar to the trunc function for numbers. , work with Date objects directly and not use date_trunc. These SQL-standard functions all return values based on the start. Share. date_trunc ( text, timestamp) → timestamp. 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. 000000の場合3 Answers. Table 9. Test. 2. 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. 1. Various built-in functions, operators, clauses, etc. trunc() will set that to 00:00:00. 2) and found the date_trunc function extremely useful for easily matching time stamps between certain days/months/etc. , 2000-12-31. 2 Answers. 9. My Postgres version: "PostgreSQL 9. create index on test (date_trunc('month', foo::timestamp )); the problem with foo at time zone 'GMT' is that the expression foo at time zone 'GMT' is not itself immutable. These queries work fine in oracle but am in the process of converting it to a postgres query but it complains. to_char(date_trunc('quarter', date '2015-01-01')::date - 1, 'yyyy-q'); Share. 600. 0 psql date_trunc issue. You cannot use the date_part of week when using DATE_TRUNC on an INTERVAL. Extract isn't quite the same as date_trunc though. 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. This function with datetime or string argument is deprecated, use DATE_TRUNC instead. 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. –0. 9. You're storing timestamps, not just dates, and you want to group by day not by number of previous events. Closed. Like: SELECT to_char("date", 'DD/MM/YYYY') FROM mytable; e. 3 Answers. 次のように実例を示すとわかりやすいです。. Follow. But it can be a bit simpler / faster: SELECT extract (days. Need group data by each line time interval, e. See full list on database. Example #1 – by using the date_trunc function. SELECT date_trunc('day', "extras"->>'sent') AS date , count(*) AS "value" FROM "document" GROUP BY 1. 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. A weird way to number weeks but might be what the OP is after :) – Andomar. It's not immutable because it depends on the sessions time zone setting. Truncate to specified precision; see Section 9. 3), and I'm getting. 3 . So fellow SQL aficionado's how to take the following WHERE clause in PostgreSQL and convert it to SQLite3 without using a compiled extension: WHERE DATE_TRUNC ('day', c. TRUNCATE quickly removes all rows from a set of tables. RTRIM. e. How to update a part of a timestamp field in postgres? 0. So both dates have already been created and inserted into the tables, here is an example of the dates: timestamp without time zone = 2012-09-19 18:13:26. the postgres server timezone. In the following example, you must migrate an Oracle database (DB time zone MET) to a PostgreSQL database, in which the application code uses SYSDATE. PostgreSQL provides a number of functions that return values related to the current date and time. Date_Trunc varies parts of the date/time: century, year, month, day, hour, minute, second, millisecond,. date_trunc('hour', timestamp '2001-02-16 20:38:40') → 2001-02-16 20:00:00:. Modified 10 years, 9 months ago. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. You may create an overloaded TRUNC function in Postgresql. In order to ignore seconds, you can use date_trunc () function. Viewed 11k times. 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. date_part(text, timestamp) or date_part(text, interval) Return Type: double precision. For example, if I have 2011/05/26 09:00:00, I want 2011/05/26. The PostgreSQL TRUNC() function returns a number truncated to a whole number or truncated to the specified decimal places. Mathematical operators are provided for many PostgreSQL types. 456,2) AS "Truncate upto 2 decimal"; Sample Output: Truncate upto 2 decimal ----- 67. 599Z'::timestamp); date_trunc ----- 2022-06-15 08:27:00 An alternative is to round the seconds with ::timestamp(0) - see this other answer. I have searched and found. Example:The issue could either be rounding back to GMT during the ::DATE cast (within the query), could be similar casting due to the ` - interval '1 day'` part, or could potentially be caused during the 'printing' phase (e. Table 9. 1. Current Date/Time. PostgreSQL: Documentation: 9. edited Aug 18, 2015 at 10:57. hot to add one month to the required column by substracting one day from it in postgresql. 2019-04-01) Share I need to query for a date like the one in my code, and in postgreSQL i found date_trunc to "cut off" unnecessary information from the date. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see Section 9. , hour, week, or month and returns the truncated timestamp or interval with a level of precision. The following illustrates the. date_trunc('hour', timestamp '2001-02-16 20:38:40') → 2001-02-16 20:00:00. ) field selects to which precision to truncate the input value. I see that date_trunc function returns timestamp and intervals cannot be cast to date type: select current_date -. (Values of type date and time are cast automatically to timestamp or interval, respectively. For. A primer on working with time in Postgres. SELECT * FROM stud_cmp WHERE DATE_TRUNC ('day', start_date) = '2020-01-01' :: timestamp; In the above example, after comparing the start date and with date_trunc functions, it will display the three records which contain the. 3. The date_trunc() function is used to truncate to specified precision. first day of year + current week * 7 days = closest preceding date with same day of week as the first day of the year. , line 01 (2011/01/03 19:18:00. – zhrist. 5. confusingly at time. The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. Here's the best GROUP BY query I have so far: SELECT d. 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. You can round off a timestamp to one of these units of time: If the above timestamp were rounded down to 'day', the result is: to_char and all of the formatting functions let you query time however you want. See Postgres Date/Time Functions and Operators for more infoI am using Datagrip for Postgresql. select date_trunc ('minute', created_at), -- or hour, day, week, month, year count(1) from users group by 1. Yes, I believe that's the case. MySQL- Truncating Date-Time in a query. But what exactly are you trying to achieve there? can't you just use intime - (current_date - 1) and use the resulting interval – user330315I am trying to use the Date_Trunc for MONTH function in a SQL statement but somehow it is not working for me. The "epoch" of a timestamp represents the number of seconds elapsed since a certain time and date (1st Jan 1970, 00:00:00). , are used in Postgres to store and manipulate the dates. The problem is date_trunc('week', datetime_column) function considers Monday as the week start day and some of my customers user different start day in calendar (like Saturday). Table 9-27 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. Next. The below example shows the group by month by using the date_trunc function. For instance, the “BETWEEN” clause, the “DATE_TRUNC()” function, and the basic comparison operators like “=”, “!=”, “>=” etc. The day (of the month) field (1 - 31). These SQL-standard functions all return values based on. 2: date_trunc('hour', timestamp '2001-02-16 20:38:40'). AT TIME ZONE. Pictorial Presentation of PostgreSQL DATE_TRUNC() function. The function date_trunc is conceptually similar to the trunc function for numbers. Let’s see the following example. Use the DATE_TRUNC() function if you want to retrieve a date or time with a specific precision from a PostgreSQL database. 0 did not follow the conventional numbering of millennia, but just returned the year field divided by 1000. 9. 0) $$ LANGUAGE SQL; Generally rounding up to. Viewed 1k times 0 Context: I have a dataset in Superset of parts - item ids, order year, avg annual cost. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. Getting results between two dates in PostgreSQL. Teams. How to Exclude Current or Partial Weeks in PostgreSQL. I have a table partitioned per month (timestamp column). The end date is also simplified; just add exactly one month. SELECT date_trunc ('day', time), "PositionReport". 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). Author: John Naylor <john. The DATE_TRUNC () function in Postgres truncate a date or time value to a specific precision. 5. date_trunc. Partition by date range PostgreSQL scans all partitions. 4. I want to be able to: apply a mathematical operator to subtract 1 day filter it . 4. Issue in creating a function in PostgreSQL using date_trunc. These SQL-standard functions all return values based on. extract() complies with the SQL standard, date_part() is a Postgres specific query. CREATE OR REPLACE FUNCTION last_day(date) RETURNS date AS $$ SELECT (date_trunc('MONTH', $1) + INTERVAL. 0. PostgreSQL DATE_TRUNC by 2 Weeks. Truncate it to the start of the day (still timestamp without time zone ): date_trunc ('day', (now () AT TIME ZONE 'America/New_York')) Get the. 300) must add 10 minutes and collect all the line that are within this time interval, or , all records that are between 19:18:00. 0) $$ LANGUAGE sql;Data Type Formatting Functions. Note that the latter returns a timestamp with time zone, not a timestamp value. Data granularity measures the level of detail in a data structure. g. date_trunc関数. 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. The function date_trunc is conceptually similar to the trunc function for numbers. Thanks, but just for your own sake, you should maybe consider making use of Hibernate APIs if you want to get the best out of your ORM. This gives the date rounded to the start of the quarter, e. A more specific answer is: where generated_time >= date_trunc ('hour', current_timestamp) and generated_time < date_trunc ('hour', current_timestamp) + interval '1 hour'. The range of values for date values in PostgreSQL is 4713 BC to 5874897 AD. Table 9. Syntax: date_trunc(text, timestamp) Return Type: timestamp. 3 . PostgreSQL Version: 9. date_trunc. 9. 7. -- 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。. In PostgreSQL I am extracting hour from the timestamp using below query. Here is a function that mimics postgres' DATE_TRUNC contract using the DATE_FORMAT mysql function that @Charles has recommended above. PostgreSQL 如何在postgres中截取日期 在本文中，我们将介绍如何使用PostgreSQL数据库中的函数和操作符来截取日期。 阅读更多：PostgreSQL 教程 1. Learn more about TeamsExample 3: PostgreSQL TRUNC() function. The basic syntax of the DATE_TRUNC function is as shown below:In PostgreSQL, the date_trunc() function truncates a date/time value to a specified precision. Looks like I could go your way or just go full native query instead. For data type TIMESTAMP WITH LOCAL TIME ZONE this function is calculated within. 「2020-09-01」のようなdate型、またタイムスタンプ型の値から「2020」や「9」のように年のみ、月のみなど特定の単位の値だけ取り出したい場合がある。. 1) precision The precision argument specifies fractional seconds precision of the second. select date_trunc('minute', now()) Edit: This truncates to the most recent minute. 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. source is a value expression of type timestamp or interval. It also uses this format for inserting data into a date. Sorted by: 2. (Values of type date and time are cast automatically to timestamp or interval, respectively. Truncate a date in Postgres (latest version) 0. datepart. 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. g. 2. Consequently, the timestamp will be rounded/truncated based on the specified date field. These SQL-standard functions all return values based on the start. In this case you still need to calculate the start date of the month you need, but that should be straight forward in any number of ways. 31 illustrates the behaviors of the basic arithmetic operators ( +, *, etc. postgresql时间差计算. To have one row per minute, even when there's no data, you'll want to use generate _ series. g: SELECT (date_trunc('week', now() + interval '1 day') - interval '1 day')::DATE; date ------------ 2019-06-16 As per documentation , date_trunc() accepts values of type date and timestamp and returns a timestamp (thus the cast at the end). In Postgresql, we can also add a year to the current date using the INTERVAL data type. 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. So using date_trunc('week',now())-'1 s'::interval; on the right side of your date operator should work. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. CREATE FUNCTION TRUNC ( dttm TIMESTAMP ) RETURNS TIMESTAMP AS $$ SELECT DATE_TRUNC('DAY',$1); $$ LANGUAGE SQL IMMUTABLE; select TRUNC(NOW()::timestamp); 12. In fact extract() gets re-written to date_part() - check the execution plan and you will see. This function helps in manipulating numbers as required. Unless otherwise noted, operators shown as. So fellow SQL aficionado's how to take the following WHERE clause in PostgreSQL and convert it to SQLite3 without using a compiled extension: WHERE DATE_TRUNC ('day', c. Share. create index mytable_ts_day on mytable (extract (day from ts)) and this index then can be used for a matching expression like extract (day from ts) = 9, or any other operator on. Use the below command: SELECT date_trunc ('week', timestamp'2021-08-23 19:14:20'); Postgresql date_trunc week. Here’s the current timestamp. Both are b-tree indexable operations. x: CriteriaBuilder cb = entityManager. 4 shows the mathematical operators that are available for the standard numeric types. You ae mixing Oracle syntax with Postgres (date_trunc()). It looks like this: select date_trunc('month',now()). The following illustrates the syntax of the date_trunc function: date_trunc ('datepart', field)The PostgreSQL date_trunc() function truncates a specified timestamp or interval value to the specified part and returns the result. In time-series analysis, the granularity could be on intervals of years, quarters, months, weeks, days, or hours. Example of grouping sales from orders by month: select SUM(amount) as sales, date_trunc('month', created_at) as date from orders group by date order by date DESC; In Postgresql, to truncate or extract the week of the timestamp value, pass the week as a string to the date_trunc function. gradovenko mentioned this issue on Dec 7, 2021. Hyperloglog is a Postgres extension for doing high-compression storage and query approximations. ). Either truncate the timestamp by minutes using date_trunc, which will return a timestamp without seconds, or use to_char if it is only about formatting the output: SELECT date_trunc ('minute',VISIT_DATE) FROM t; SELECT to_char (VISIT_DATE,'yyyy-mm-dd hh24:mi') FROM t; Demo: I have a slow query that generates a report of account activity per week over the past year. As far as I understand you want to change the day of the month to 8. 2. If you want just the date in the current time zone, cast to a date. 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. So instead of having. - It retrieves the trimmed part with a specific precision level. This function truncates a date/time value to a specified precision. Truncate date in units other than default choices using date_trunc (Postgres 9. The field is an identifier or string that selects what field to be extracted from the source value. 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). What is the linq equivalent to sql trunc date? 0. Yes, that is how you use date_trunc. AT TIME ZONE. 2. 基本的な使い方を見ていこう。. こういった場合、extract関数を使うことで簡単に年月日を取得することができる。. , year, month, day, etc. If, however, the number of different days is significantly lower, the problem is that PostgreSQL has no way to estimate the distribution of date_trunc 's results unless you create an index: CREATE INDEX ON test (date_trunc ('day', updated_at)); If updated_at is a timestamp without time zone, that will work fine.