2. The DATE_TRUNC function truncates a timestamp expression or literal based on the date part that you specify, such as hour, day, or month. Or simpler, use the column number: group by 1 (if the expression is the first column in the select clause). These SQL-standard functions all return values based on. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see Section 9. A cast to timestamp (0) or timestamptz (0) rounds to full seconds: Fractions are not stored in table columns of this type. 1. date_trunc関数の第一引数には任意の値を文字列として指定する。. 30 shows the available functions for date/time value processing, with details appearing in the following subsections. decade. In postgres, you could phrase this as: date_trunc ('quarter', current_date) + interval '3 months' - interval '1 day'. 2: date_trunc('hour', timestamp '2001-02-16 20:38:40'). Translate to PostgreSQL generate_series #2144. 5. 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;I have a slow query that generates a report of account activity per week over the past year. Instead, you should use to_char to format the date when you query it, or format it in the client application. The table currently has nearly 5 million rows and this query currently takes 8 seconds to execute. The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. I need it to return april 22. g. We have used the date_trunc function with the where clause to compare the date in PostgreSQL as follows. date_trunc(text, timestamp) timestamp: Truncate to specified precision; see also Section 9. MySQL- Truncating Date-Time in a query. Partition by date range PostgreSQL scans all partitions. The date_trunc() function is used to truncate to specified precision. 2: date_trunc('hour', timestamp '2001-02-16 20:38:40'). ERROR: function date_trunc(unknown, text) does not exist HINT: No function matches the given. Truncate a date in Postgres (latest version) 0. I can cast the PG date::timestamp(0) which gets me close but as would be expected the date is rounded. For formatting functions, refer to Section 9. PostgreSQL database has a default time zone setting, the operating system’s time zone. SELECT date_trunc ( 'day', to_timestamp (requests. Hyperloglog is a Postgres extension for doing high-compression storage and query approximations. It will return the date truncated to month precision, e. x: CriteriaBuilder cb = entityManager. The Timescale extension for PostgreSQL gives the ability to group by arbitrary time intervals. ktkr！ と思ったのですが、、、 SELECT CURRENT_DATE; でよかったorz. Practical examples would include analyzing company’s. "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. ). , hour, week, or month and returns the truncated timestamp or interval with a level of precision. Truncate to specified precision. Postgres offers several date-time functions to deal with temporal data. Use date_trunc (): where generated_time >= date_trunc ('hour', current_timestamp) That actually assumes no future times in your table. Use the date_trunc method to truncate off the day (or whatever else you want, e. Note: All the date field parts other than the targeted. century. 1. The straightforward way to do it is like this: date_trunc ('hour', val) + date_part ('minute', val)::int / 5 * interval '5 min'. 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. date; The results:見つけたのがdate_trunc関数。 date_trunc関数 「おぉ、イイネ！（・∀・）ﾆﾔﾆﾔ」となり、早速実験。 SELECT date_trunc('day', now()); 結果を見てみると 2013-05-01 00:00:00+0. 600 is 10 minutes in seconds. 0. This is how I made it: CREATE OR REPLACE FUNCTION public. 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. g. For partition naming you could use year and week number in the year YYWW:. PostgreSQL releases before 8. This is an example:date_trunc('week', column_name) It uses the ISO definition of a week (as does Oracle's 'IW' ) so you need to apply the same date logic you used in Oracle to get the non-standard start of the week: date_trunc('week', column_name + 1) - 12 Answers. . Q&A for work. My Postgres version: "PostgreSQL 9. GROUP BY 1. The precision values are a subset of the field identifiers that can be used with the EXTRACT() and DATE_PART() functions. Improve this answer. 所以在此只说明Postgresql 中的TRUNC取断函数. Looks like I could go your way or just go full native query instead. postgres sql, date_trunc without extra zeroes. date_trunc関数. code:Apache Superset PostgreSQL 'function date_trunc(unknown, bigint) does not exist. Split a string on a specified delimiter and return nth substring. 9. この. PostgreSQL Version: 9. 0) $$ LANGUAGE sql;Data Type Formatting Functions. 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. (Values of type date and time are cast automatically to timestamp or interval, respectively. Table 9. 2. The Oracle code that I posted returns april 22, so I need postgres to do the same. The PostgreSQL EXTRACT() function. select extract (isoyear from current_date); select extract (week from current_date); But there seems to be no inverse. SELECT CURRENT_TIMESTAMP::DATE If you need to use culture specific formatting in your. The below will index but returns with timestamp added to date which. or you can create your own. SELECT date_trunc ('day', time), "PositionReport". How to perform date_trunc query in Postgres using SQLAlchemy. This is an excerpt from my sql query. Here’s the current timestamp. Syntax. In Postgres, DATE_TRUNC () has the following intervals. select date_trunc('minute', now()) Edit: This truncates to the most recent minute. DATE_TRUNC関数 日付値を切り捨てる. Finally, it returns the truncated part with a specific precision level. I want to use date_trunc function in PostgreSQL on my datetime column to aggregate data in a week. And best solution is 1st that suggested by marco-mariani. In the first example, we have not used the aggregate function, in the second example, we have used the aggregate function. PostgreSQL: Greatest will return the largest non-null expression, or null if all expressions are null. 3. The real value returned by the CURRENT_TIMESTAMP was ‘2023-06-17 14:45:08. The function date_trunc is conceptually similar to the trunc function for numbers. day. You can now use date_trunc (text, timestamp) with Doctrine! Note: You can easily adapt this code for every additional Postgres/MySQL function. The text was updated successfully, but these errors were encountered: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). (Values of type date and time are cast automatically to timestamp or. The date_trunc(text, timestamptz) variant seems a bit under-documented, so here are my findings:. PostgreSQL group timestamp by date and truncate time. Practical examples would include analyzing company’s quarterly. 1. UPPER関数 大文字に変換する. 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 * FROM. Mathematical Functions and Operators #. 9 postgres sql, date_trunc without extra zeroes. 1. morland@gmail. (Values of type date and time are cast automatically, to timestamp or interval respectively. 31 shows the available functions for date/time value processing, with details appearing in the following subsections. the postgres server timezone. A primer on working with time in Postgres. Getting results between two dates in PostgreSQL. The second one which use DATE_TRUNC will tranc any date to the first day of the month. Truncate datetime column in MySQL query. 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. date_trunc. to_char(date_trunc('quarter', date '2015-01-01')::date - 1, 'yyyy-q'); Share. of ("Asia/Tehran")). g. postgres sql, date_trunc without extra zeroes. 2020-04-01, and has the advantage that subsequent steps in the pipeline can read it like a normal date. date_created <= { {date_range_end. Mathematical operators are provided for many PostgreSQL types. Also, you need to study the week in snowflake. 9. DATE_TRUNC (‘ [interval]’, time_column) The time_column is the database column that contains the timestamp you'd like to round, and [interval] dictates your desired precision level. 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. Current Date/Time. That is still a distinguishable value. The DATE_TRUNC() function is particularly useful for time series analysis to understand how a value changes over time. They truncate all parts of the date up to kind which allows grouping or. In simple terms, DATE_TRUNC () extracts a TIMESTAMP/INTERVAL and truncates it to a specific level of precision. Well, there are many ways to handle this, but the efficient way is to use date_trunc, as mentioned in the privous answer. See the table of available functions for date/time value processing and the examples of date_trunc usage. date_trunc('hour', timestamp '2001-02-16 20:38:40') → 2001-02-16 20:00:00. if you want timestamp instead of timestamptz cast the date to timestamp first. In PostgreSQL I am extracting hour from the timestamp using below query. 9. Truncation means setting specific parts of the date or time to zero or a default value while keeping the more significant parts unchanged. Ordering by month & year numbers in Postgres. I would like to change the date into month. Finding the last date of the previous quarter from current date in PostgreSQL. Basically this expression gives you the last day of the current quarter (provided that you remove the last closing parenthese, which otherwise is a syntax error). The basic syntax of the DATE_TRUNC function is as shown below:. 299. table t Returns. , and a timestamp. 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. The DATE_TRUNC() function reduces the granularity of a timestamp. This gives the date rounded to the start of the quarter, e. only date_trunc(text,interval) and date_trunc(text,timestamp) are immutable. Its return type is TIMESTAMP with TIMEZONE. 9. date_trunc関数の第一引数には任意の値を文字列として指定する。. Fiddle with your system until. 4. The day (of the month) field (1 - 31). PostgreSQL: Documentation: 9. , date/time types) we describe the actual behavior in subsequent sections. In existing versions of Postgres, you can use arithmetic: select t. CURRENT_TIMESTAMP関数 現在の日時を求める. I want to have it trucated according to the displayed timezone. 0) $$. 1 Answer Sorted by: 2 They both do very different things. The field is an identifier or string that selects what field to be extracted from the source value. For example I need to get number of sales each week. As far as I know, if I want to trunc date, I need to use the date_trunc() function in posgresql. 2. This can be combined with INTERVAL computations and the extract operation to do pretty much anything you need to with dates and times. If you want both quarter and year you can use date_trunc: SELECT date_trunc ('quarter', published_date) AS quarter. start_date) <= DATE_TRUNC ('day', q. It is slightly dirty, though, because the minimum time interval is an implementation detail of current Postgres versions. Share. 3 . The PostgreSQL CURRENT_TIMESTAMP () function returns the current date and time with time zone. The real usefu. 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. PostgreSQL provides a number of functions that return values related to the current date and time. maybe the -interval '1 day' changes the class so it is printed as a datetime instead of a date). Follow answered Feb 26, 2018 at 23:30. I'm trying to create a string with the week number and the first and last date on that week, like this: 'W41 04/10-10/10' I was able to create a formula on Google Sheets that solve my problem and now I need to do this on PostgreSQL. Isolating hour-of-day and day-of-week with EXTRACT function. 当然PostgreSQl 也有大量的时间函数,详情请移步postgresql时间日期函数总结. 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. I've looked around and I can't figure out the right syntax for accessing the month and comparing with the current month. date=to_char (date_trunc ('day', se. You might need to add explicit type casts. 8. date_trunc still gives me the whole date. However, Postgres' date type doesThe PostgreSQL date_trunc() function truncates a specified timestamp or interval value to the specified part and returns the result. 000000の場合3 Answers. The full docs in section 9. I have searched and found. PostgreSQL dynamic date_trunc function rounding up exactly to given timestamp. milliseconds. lead_id) as "# New Leads" from leads l where l. When used to aggregate data, it allows you to find time-based trends like daily purchases or messages per second. 0. date_trunc () The return type of the date_trunc function is a timestamp. Postgresql extract monthYear from a date to be compared. On the other hand you can use date_trunc function. 9. 9. I would like to change the date into month. ISFINITE. For types without standard mathematical conventions (e. The function date_trunc is conceptually similar to the trunc function for numbers. now (). and while the condition is > '2018-10-01' then all dates in the month October will not be shown in the result. For data type TIMESTAMP WITH LOCAL TIME ZONE this function is calculated within. We are also looking at upgrading to a newer version of Postgres but that is further out. 2: date_trunc('hour', timestamp '2001-02-16 20:38:40'). Date and time input is accepted in almost any reasonable format, including ISO 8601, SQL -compatible, traditional POSTGRES, and others. select date_trunc('year', current_date)Well, In postgres, it seems there's no such function equivalent to LAST_DAY() available in oracle. The function date_trunc is conceptually similar to the trunc function for numbers. Learn more about Teams3 Answers. PostgreSQL provides a number of functions that return values related to the current date and time. The source must be a value expression of type timestamp, time, or interval. 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. 「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。. In this case, for the month before last I'd write:Learn how to round or truncate timestamps in PostgreSQL for effective time-based grouping using the date_trunc function. The subquery is not strictly needed, but it makes the code easier to read. PostgreSQL provides a number of functions that return values related to the current date and time. SELECT my_date::date::timestamp. date_trunc('month', '{{ date. Integer division truncates. 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. 1 Answer. date_created) )AS DAY, this is my output 2013-02-04 00:00:00+00. To have one row per minute, even when there's no data, you'll want to use generate _ series. The following example illustrates how to use the CURRENT_TIME function with the precision set to 2: The CURRENT_TIME function can be used as the default value of TIME columns. 9. PostgreSQL Date Functions (and 7 Ways to Use Them in Business Analysis) Facebook's Aha Moment Is Simpler Than You Think. Syntax: date_trunc(text, timestamp) Return Type: timestamp. But the week starts on Monday in Postgres by default. date_trunc('field', source) source is a value expression of type timestamp (values of type date and time are cast automatically). 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。. 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. Any code developed for PL/Java and Java 8 or newer is strongly encouraged to use these types for date/time manipulations, for their much better fit to the PostgreSQL types. When used with a timestamp, truncates the timestamp to a date (day) value and returns a timestamp with or without time zone depending on type of the argument. An alternative pproach is to use to_char function. Here is a function that mimics postgres' DATE_TRUNC contract using the DATE_FORMAT mysql function that @Charles has recommended above. date) going over the. Sorted by: 1. 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. TRUNCATE quickly removes all rows from a set of tables. postgresql ignore milliseconds from timestamp when doing a select statement. Table 9. 0. 2 do mention both forms though. In PostgreSQL, DATE_TRUNC() is a built-in date function that truncates/trims the unnecessary part from the date/time. . 6. PostgreSQL is a powerful database and includes various functions for managing timestamps and date times. Postgres truncate timestamp gives slightly unexpected output. 61 Avg. The following illustrates the syntax of the date_trunc function: Date_trunc is a function that returns a date part of a date or a time part of a time. ADVERTISEMENT. 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. date_trunc can be really helpful if you want to roll up time fields and count by day or month. For. DATE_TRUNC() will return an interval or timestamp rather than a number. The cast to date ( day::date) does that implicitly. You may create an overloaded TRUNC function in Postgresql. 0. GMB GMB. 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. Various built-in functions, operators, clauses, etc. 1) 2. この. How to use date_trunc in PostgreSQL to truncate to 100 milliseconds? 1. 7. Jun 2 at 11:46. Its Java equivalent is:I have a PostgreSQL table called tickets_details, which has many columns and is constantly updated only on the rows of the current day, it also inserts thousands of rows of the current day that have. I see that date_trunc function returns timestamp and intervals cannot be cast to date type: select current_date -. 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. Based on the parts extracted, create a new datetime. getCriteriaBuilder (); CriteriaQuery<Date> query = cb. custom DATE_TRUNC timeframes. : select date_trunc_interval('15 minutes', timestamp '2020-02-16 20:48:40'); date_trunc_interval ----- 2020-02-16 20:45:00 (1 row) With this addition, it might be possible to turn the existing. The query worked fine in principle so I'm trying to integrate it in Java. The output snippet shows that the DATE_PART() function pulls out the year from the given date. 9. milliseconds contains seconds & microseconds contains milliseconds (and thus seconds too). date_trunc “truncates” a TIMESTAMP or an INTERVAL value based on a specified date part (e. date_trunc ( text, timestamp) → timestamp. g. Its type is timestamp without time zone. Current Date/Time. Trimming trailing :00 from output after date_trunc. date_trunc. These SQL-standard functions all return values based on the start time of the. The function date_trunc is conceptually similar to the trunc function for numbers. The function date_trunc is conceptually similar to the trunc function for numbers. Specifying the time zone in date_trunc is not supported in Postgresql 11. It can also return a number truncated to the whole number if no precision is defined. What. update mytable set starts_at = date_trunc('day', due_at), ends_at = date_trunc('day', due_at) + interval '1' day - interval '1' minute You could also phrase this as:. In your example, you could use: SELECT * FROM myTable WHERE date_trunc('day', dt) = 'YYYY-MM-DD'; If you are running this query regularly, it is possible to create an index using the date_trunc function as well: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 provides two very similar functions DATE_PART and EXTRACT with different syntax, but identical (DATE_PART returns a double, which can lead to some loss of precision) behavior. I want to use date_trunc function in PostgreSQL on my datetime column to aggregate data in a week. The DATE_TRUNC () function is particularly useful for time series analysis to understand how a value changes over time. But then you cannot use ordinal positions as. date_trunc. Read: Postgresql date_trunc function Postgresql date add year. Explore options like 'second', 'minute', 'hour', 'day', or 'month' to tailor your data analysis. PostgreSQL's date_trunc in mySQL. It also uses this format for inserting data into a date. WW truncates date to the nearest previous day same to the first day of week of the year. reg = 'PH-BVA' GROUP BY 1, "PositionReport". This way, timescaledb's gapfill function from smaller interfal (day) should be carried on the longer time interval. 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. (Values of type date and time are cast automatically to timestamp or interval, respectively. A regular select date_trunc('month', t. CURRENT_DATE関数 現在の日付を求める. ; some date parts include others: i. 3. g. date 、 time 、または timestamp を指定された精度に切り捨てます。. A bigint is not "a timestamp", so you must convert the number to a date before you can apply date_trunc () on it: Select date_trunc ('day', to_timestamp (rp. The first day of a week (for format element 'week') is defined by the parameter NLS_FIRST_DAY_OF_WEEK (also see ALTER SESSION and ALTER SYSTEM ). Extract year from postgres date. 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， We have used the date_trunc function with the where clause to compare the date in PostgreSQL as follows. g. Input Format: Dates in yellow are the dates to aggregate sales on. 3 . So using date_trunc('week',now())-'1 s'::interval; on the right side of your date operator should work. SELECT date_trunc('day', "extras"->>'sent') AS date , count(*) AS "value" FROM "document" GROUP BY 1. I want to generate a series of months. Current Date/Time. 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 date_trunc function truncates a TIMESTAMP or an INTERVAL value based on a specified date part e. DATE_TRUNC('datepart', timestamp) Arguments. Say, you can truncate it to the nearest minute, hour, day, month, etc. ts BETWEEN a AND b is just a shorthand for writing ts >= a and ts <= b. Truncate a date in Postgres (latest version) 1. In PostgreSQL, the DATE_TRUNC function is used to truncate a date, time, or timestamp value to a specified precision. extract関数の場合は、extract (month from request_time)という書き方だったが、date_trunc関数ではmonthをシングルクォーテーションで囲む必要がある。. 1994-10-27. I have a table with a date field in timestamp format (ex: 2016-11-01 00:00:00). For formatting functions, refer to Section 9. date_trunc() "rounds" the value to the specified precision. Say, you can truncate it to the nearest minute, hour, day, month, etc. 0. SELECT CODE, to_char (DATE, 'YYYY-MM'), count (CODE) FROM employee where group by CODE, to_char (DATE, 'YYYY-MM') Depending on whether you want the result as text or a date, you can also write it like this: SELECT CODE, date_trunc ('month', DATE), COUNT (*) FROM employee GROUP BY CODE, date_trunc ('month', DATE);. 1. 45 (1 row) Previous: TAN function Next: PostgreSQL ARRAY functions ARRAY_APPEND function Follow us on Facebook and Twitter for. This uses PostgreSQL’s date_trunc() function to return the results we want. WHERE time >= date_trunc('hour', now()) - INTERVAL '1 hour' AND time < (date_trunc('hour', now())) However to work with our current dataset, now() won't work and as PostgreSQL doesn't support variable declarations, it's out of scope to demonstrate further, if you ran that query, with the WHERE clause at 2022-01-26 2:30:00 then it would. 456,2) AS "Truncate upto 2 decimal"; Sample Output: Truncate upto 2 decimal ----- 67. Note: This shows two methods of doing the conversion, the first is the standard method. I. 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. However, I am trying to do a select and ignore milliseconds. date_trunc('hour', timestamp '2001-02-16 20:38:40') → 2001-02-16 20:00:00:. 2. For types without standard mathematical conventions (e. 4. Introduction to the PostgreSQL date_trunc function. The seconds field, including fractional. Simplify calculation of months between 2 dates (postgresql) 0. 5. You can also use the INTERVAL value with the date_part() function that represents the duration of any event. The DATE type in PostgreSQL can store a date without an associated time value: PostgreSQL uses 4 bytes to store a date value. Your solution and mine give. SELECT * FROM Conference WHERE date_start >= date_trunc ('month', current_date - interval '1' month) and date_start <. That truncates the date according to the timezone of the (Grafana) client resp. callsign FROM tvh_aircraft. e. Mean you. date_trunc('field', source) source is a value expression of type timestamp (values of type date and time are cast automatically). For example, if I have 2011/05/26 09:00:00, I want 2011/05/26. l_date is the column where I would pull the date from. 9. Jun 27, 2014. ). 2. Is that what you want?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). (Values of type date and time are cast automatically to timestamp or interval, respectively. datepart. The seconds field, including fractional. +01 +02 etc depends on your time locale's daylight saving rules.