SQL Server : -- Get difference in days SELECT DATEDIFF ( dd, '2022-09-01', '2022-09-05'); # 4. Date or DateTime could be one of them. DATE_SUB. In MySql the syntax of DATEDIFF is different: DATEDIFF (date1, date2) and returns the difference date1 - date2 in days. You can put literal date expressions or column names of date type. expr1 and expr2 are date or date-and-time expressions. UNIT can be SECOND MINUTE HOUR DAY WEEK. So, for example, DATEDIFF (last_order_date,. Window functions are a key SQL resource. 2 Compare and Report Differences in Catalogs. Date values are interpreted as DateTime with the time part set to 00:00:00 by default. DATEDIFF () returns ( expr1 – expr2) expressed as a value in days from one date to the other. Each subclause provides a subquery that produces a result set, and associates a name with the subquery. Based in the answer from dbdemon, you could use a CASE: CREATE TABLE t1 ( id int unsigned primary key, date1 date, date2 date ); INSERT INTO t1 (id, date1, date2) VALUES (1, '2017-12-29', '2018-01-05'), (2, '2018-02-20', '2018-03-05'); SELECT. Improve this answer. SELECT log, TIMESTAMPDIFF(year, createddate, waitingtime) AS YearDiff, TIMESTAMPDIFF(month, createddate, waitingtime) AS. @asfasas You can always convert the results using a proper mask. util. The DATEDIFF () function calculates the difference in days between two DATE values. The YRDIF function can compute a person’s age. For the DATE and DATETIME range descriptions, “supported” means that although earlier values might work, there is no guarantee. MySQL the TIMESTAMPDIFF () returns a value after subtracting a datetime expression from another. numeric (dif)) sqldf ("select * from DF1") ## dif ## 1 1. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part '00:00:00' where necessary. What this portion is doing is figuring out the number of days that have passed between 0 (If. One of the many unwritten Rules about Relational databases - Dates have no format. We would use the same transaction to debit ACC1 and credit ACC2 with a fund of $100. The DATE_ADD function adds an interval to a DATE or DATETIME value. 引数は、結果を表す単位と、差異を取る 2. 날짜차이 계산하기 : DATEDIFF (e. Most modern versions of MyQL replace the database_name with * in the grant privileges command after you select the database that you want to use. In this article, we learned how to do SQL subtract dates using the DATEDIFF function. The way it works is, you provide the two values to compare, and TIMEDIFF() subtracts the second value from the first, then returns the result as a time value. In this page, we have shown an advanced MySQL date calculation using the following functions : CURDATE() function which returns the current date of the computer, YEAR() function which returns the year of the specified date, MONTH() function which returns the month of the specified date, DAY() function which. The Try-MySQL Editor at w3schools. DBDiff. TIMESTAMP - format: YYYY-MM-DD HH:MI:SS. Example: In this example, we will calculate a number of months between two specific dates using. No other values for basis are valid when computing a person’s age. In case you use a DATE value, the TIMESTAMPDIFF function treats it as a DATETIME value whose time part is. Format2. PyMySQL works with MySQL 5. 1 Answer. SELECT DATEDIFF (month,'2011-03-07' , '2021-06-24'); In this above example, you can find the number of months between the date of starting and ending. Used with %X. MySQL DATEDIFF () computes and returns the value of date1– date2. Syntax of MySQL DATEDIFF () DATEDIFF (date1, date2) Code language: SQL (Structured Query Language) (sql) Where, ‘date1’ and ‘date2’ are two date or. Introduction to MySQL DATE_ADD function. (05-10 to 05-31) = 21 days (2014-06 to 2015-03) = 9 months (03-01 to 03-09) = 9 days total is 9 months and 30 days. While SQL is a programming language used to work with data in relational databases, MySQL is an open-source database product that implements the SQL standard. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. Working With Time Zones. Share mysql> SELECT something FROM tbl_name-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col; The query also selects rows with dates that lie in the future. or, at least, none that you or I need worry about. MySQL query using alias to count certain years from DATETIME. The following example defines CTEs named cte1 and cte2 in the WITH clause, and refers to them in the top. Get your own SQL server SQL Statement: Edit the SQL Statement, and click "Run SQL" to see the result. The DATEDIFF function has two arguments; we specify the dates for which we want to find the difference. Required. There are no user contributed notes for this page. Try this one: select * from MyTab T where date_add (T. It works if my beginning date is the first of january and the end date the 31st of December, but does not if it stars somewhere else during the year. Select datediff (max (hire), min (hire)) as Difference From Employees Where terminated = 'NULL'. Arguments. Example. The int data type takes 4 bytes as storage size whereas. これまで2年超、業務でPostgreSQL (9. Above MySQL query has been tested and verified. Parameter 3 - End Date or Datetime Values. 2). A date value is treated as a datetime with a default time part '00:00:00'. montant / (datediff (NEW. I'm trying to obtain the age of companies in years months and days, however the calculation its not right. In this article we cover the concept of a transaction, MySQL and the ACID Model, MySQL Transaction, statements that cannot be Rolled Back and cause an implicit Commit, SAVEPOINT, ROLLBACK TO SAVEPOINT, and RELEASE. MySQL is a widely used relational database management system (RDBMS). The following query selects all rows with a date_col value from within the last 30 days: . $query="SELECT dt,dt2,year (dt) as year1,year (dt2)as year2, (year ( dt2 ) - year ( dt )) as difference FROM `dt_tb`"; $qt=mysql_query ($query); echo. In MySQL, DATEDIFF function, takes only two arguments: end date and start date: DATEDIFF(NOW(), P. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. The datepart argument can be microsecond, second, minute, hour, day, week, month, quarter, or year. Apply the same thing to the date field in your table like YEAR. bigger = later). The default column name for the DATEDIFF function is DATE_DIFF. 1. This seems to work for all the dates I throw at it. The result what I want is 2 months and not 1 month or 1 month 14 days. MySQL Data Types. MySQL Database: Restore Database. MySQL provides a set of functio. Examples below. Detailed instructions, as well as other methods for installation, can be found in Installing MySQL on Linux. This means that multiple references to a function. Query the Entities. One may be a date and another is datetime. Only the date parts of the values are used in the calculation. 4. You need to pass the date expressions as arguments to the DATEDIFF () function: The. It accepts any valid date or datetime expression. SELECT YEAR ('2015-02-31') Output is NULL. The unit argument can be MICROSECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR. Parameter 3 - End Date or Datetime Values. SQL provides super key, primary key, candidate key, alternate key, foreign key, compound key, composite key, and surrogate key. MySQL 8. If you want to diff an earlier start time against a later end time, then the former should appear before the latter in the call to TIMESTAMPDIFF. compare dates in mysql where the day, month and year are stored separately. – Tim Biegeleisen. ) how to calculate mysql date diff between two dates excluding Fridays and Saturdays as Fridays and Saturdays are off days. The MySQL DATEDIFF function is used to get the difference in days between two date values. All gists Back to GitHub Sign in Sign up Sign in Sign up You signed in with another tab or window. Year-over-year (YOY) comparisons are a popular and effective way to evaluate the performance of several kinds of organizations. Currently I am only returning 1. AVG () with ROUND () and group by. In Oracle, dates are just numbers. Note that the period arguments P1 and P2 are not date values. Once the SQL query is executed, a message appears like “Commands completed successfully”. Since the question is being tagged for mysql, I have the following implementation that works for me and I hope similar alternatives would be there for other RDBMS's. The DATEDIFF () function returns an integer that represents the number of days. For example: mysql> SELECT YEAR('2014-01-28'); Result: 2014 mysql> SELECT YEAR('2014-01-28 15:21:05'); Result: 2014 mysql> SELECT YEAR('2013-10-15'); Result: 2013 This last YEAR example would display the year portion of the. i've tried. db<>fiddle demo using MySQL. Here is the main query to get the year part from MySQL date and time field. To get the difference in seconds as we have done here, choose SECOND. 3. 1. unix (Number). W3Schools offers free online tutorials, references and exercises in all the major languages of the web. spark. The TIMESTAMPDIFF () function will then return the difference in the unit specified. e. If you prefer short options, the command looks like this: $> mysql -u finley -p db_name. DEMO: Select date from Calendar to execute YEAR () →. I'm not sure exactly how R does it. For DATEDIFF: date_or_time_expr1 and date_or_time_expr2 can be a date, time, or timestamp. 000 which is the start of the. Can be one or a combination of the following values: Day of the month as a numeric value, followed by suffix (1st, 2nd, 3rd,. MySQL - TIMESTAMPDIFF () Function. In MariaDB, DATEDIFF () is a built-in date and time function that returns the difference, in days, between two dates. The MariaDB DATEDIFF function returns the difference in days between two date values. 00 pm and the value of that column. e. date: This is the date or datetime value from which you want to get the year. It is to be noted that periods are not date values. Skip to content. MySQL SQL MySQL SELECT MySQL WHERE MySQL AND, OR, NOT MySQL ORDER BY MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN and MAX MySQL COUNT, AVG, SUM MySQL LIKE MySQL Wildcards MySQL IN MySQL BETWEEN MySQL Aliases MySQL Joins MySQL. You ask for this to be done in MySQL "accurately". To find out your SQL Server start of the week you can use @@DATEFIRST by running this: select @@DATEFIRST -- default US English = 7 (Sunday) You could change your calculation to work on days rather than weeks and dividing by 7 to get a more accurate value, which you can round as you please: MySQL: SQL Fiddle Demo. Can be one of the following: 0 - First day of week is Sunday. MySQL server uses the PASSWORD function to encrypt MySQL passwords for storage in the. What this allows you to do is pass in two TIMESTAMP or DATETIME values (or even DATE as MySQL will auto-convert) as well as the unit of time you want to base your difference on. The query also selects rows with dates that lie in the future. Access a full range of deployment options from edge to cloud. First, take the inner DATEDIFF portion. That is SQL Server syntax for converting a date to a string. To count the difference between dates in MySQL, use the DATEDIFF(enddate, startdate) function. This is the highest and broadest of our tiers, acting as a container. This MariaDB tutorial explains how to use the MariaDB DATEDIFF function with syntax and examples. Subtracts the 2nd argument from the 1st (date1 − date2). Functions that return the current date or time each are evaluated only once per query at the start of query execution. datepart The units in which DATEDIFF reports the difference between the startdate and enddate. To help keep things standardized, you should only ever work with dates / times in UTC time zone. But for all other acceptable date/time column types, julianday() (and the other date/time functions) work fine with no modifiers,. DATE () Extract the date part of a date or datetime expression. MySQL the TIMESTAMPDIFF () returns a value after subtracting a datetime expression from another. SELECT TIMEDIFF ('2007-12-31 10:02:00','2007-12-30 12:01:01'); -- result: 22:00:59, the difference in HH:MM:SS format SELECT TIMESTAMPDIFF (SECOND,'2007-12-30 12:01:01','2007-12-31 10:02:00'); -- result: 79259 the difference in seconds. Here’s a quick rundown of the functions you can use in MySQL:. )Table 12. Possible duplicate of Only show hours in MYSQL DATEDIFF – Sebastian Brosch. The date function used to returns the difference between two date or datetime values as a given unit of duration. The DATEDIFF function will return the difference count between two DateTime periods with an integer value whereas the DATEDIFF_BIG function will return its output in a big integer value. 1. For example: SELECT DATEDIFF(day, '2018-03-13', GETDATE()) AS "Difference in days";@NoChance The only caveat is that if you're using an INTEGER column for date/time (which must be epoch time as per docs), then you'd have to use the unixepoch modifier, e. Can be one of the following: 0 - First day of week is Sunday. You can specify MONTH as the unit in the first parameter: SELECT TIMESTAMPDIFF(MONTH, '2012-05-05', '2012. These functions are grouped into categories – date functions, string functions , mathematic functions, and others. The MySQL DATEDIFF function returns the number of days between two given dates. MYSQL에서 DATEDIFF, TIMEDIFF 를 이용해 날짜 및 시간을 계산해보기로 합니다. I need to find how many months there are within these two days. The various versions of MySQL supports the DATEDIFF function, namely, MySQL 5. 7 日付および時間関数. sql sql 按照精确的年份减去一年 在本文中，我们将介绍如何使用sql在日期中准确地减去一年。在某些情况下，我们可能需要对日期执行精确的减法运算，以获得准确的结果。下面将通过示例说明如何使用sql完成这个任务。 阅读更多：sql 教程 了解日期函数 在开始之前，让我们先了解一些常用的sql. In this article, we used the LAG () window function to calculate year-to-year and month-to-month differences. Find the interval between today's date and a column. SELECT ((DATEDIFF('2022-01-02', '2021-12-30'))+1 - ((WEEK('2022-01-02') - WEEK('2021-12-30')) * 2) - (case when weekday('2022-01-02') = 5 then 1 else 0 end) - (case when weekday('2021-12-30') = 4 then 1 else 0 end)) as DifD but it gives wrong count (105 days. As of MySQL 8. Mysql is comparing string instead of dates!Discussion: Use the DATEDIFF() function to retrieve the number of days between two dates in a MySQL database. What you need to do is convert it into valid format. Second parameter would be the last login time, which is already in the database. It is to be noted that two expressions must be the same type. [proc_datediff] ( @date datetime ) as begin DECLARE @diff varchar(70) DECLARE @tmpdate datetime, @years int, @months int, @days int SELECT @tmpdate = @date SELECT @years =. Spatial data types. DATETIME - format: YYYY-MM-DD HH:MI:SS. mysql> SELECT something FROM tbl_name-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col;. You use MySQL DATETIME to store a value that contains both date and time. DECLARE @startdate datetime2 = '2016-01-01 00:00:00. Add a comment. This example uses the DateDiff function to display the number of days between a given date and today. Syntax DATEDIFF ( date1, date2) Parameter Values Technical. Caveat: I work mostly with MS SQL and haven't worked with MySQL in a long time, so you may need to tweak the above. start_date: The date from which you want to calculate the difference. Sorted by: 0. If the date is zero, the YEAR () function returns 0. We’ll create three methods using several Spring Data JPA features: public interface ArticleRepository extends JpaRepository <Article, Integer> { List<Article> findAllByPublicationDate(Date publicationDate) ; List<Article. This means that multiple references to a function. 0. Share. Functions that return the current date or time each are evaluated only once per query at the start of query execution. using datediff with 1 decimal for years. It will give you exact age in years. Used with %x. YEARWEEK () Function in MySQL. , begin is a DATE value and end is a DATETIME value. As for comparing, you could compare dates that are the first days of those years and months, or you could convert the year/month pair into a number suitable for comparison (i. 00. MySQL DATEDIFF () returns the number of days between two dates or datetimes. 19, the YEAR (4) data type with an explicit display width is deprecated and you should expect support for it to be removed in a future version of MySQL. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2;EXPLANATION: In this example, the MySQL DATEDIFF() function calculates the number of days between the two dates 2023-03-07 and 2023-03-01, but with an interval adjustment. MySQL 8. The MySQL AND, OR and NOT Operators. UNIX_TIMESTAMP (ts1) - UNIX_TIMESTAMP (ts2) If you want an unsigned difference, add an ABS () around the expression. 60 sec) Insert some records in the table using insert. To get the difference in minutes, choose MINUTE; for the difference. Another simple way to cast the string to dateType in spark sql and apply sql dates and time functions on the columns like following : . The difference between startdate and enddate is expressed in days. Subtracts a specified time interval from a DATE value. 6. Share. Hope. The datediff function can return the difference between two dates in days, months, years, minutes, etc. As you can't use date functions you're going to have to make up your own. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. The following query selects all rows with a. When you query data from a DATETIME column, MySQL displays the DATETIME value in the following format: YYYY-MM-DD HH:MM:SS Code language: SQL (Structured Query Language) (sql) By default, DATETIME values range from 1000-01-01 00:00:00 to 9999. MySQL provides several functions that you can use to perform calculations on dates, for example, to calculate ages or extract parts of dates. The default is date format 1. Year to year differences are. As the previous example demonstrates, the TIMESTAMPDIFF () allows you to specify a unit for the results to be returned as (in fact, it requires you to specify the unit). Here's the expression that also caters for leap years: YEAR (date1) - YEAR (date2) - (DATE_FORMAT (date1, '%m%d') < DATE_FORMAT (date2, '%m%d')) This works because the expression (DATE_FORMAT (date1, '%m%d'). If you want to create a Carbon object from a formatted date string you can use the constructor of the class just like this:I'm trying to obtain the age of companies in years months and days, however the calculation its not right. Function will return number of days between startdate and enddate. The difference between startdate and enddate is expressed in days. compare two years data month wise in mysql. The following MySQL WHERE IN query gives rows where membership_number is either 1 , 2 or 3. For example, if DATETIMEDUE is 2014-10-19 23:59:59 and the current time is 2015-01-19 20:00:00, and you ask for the difference in months, the. You can use TIMESTAMPDIFF which returns the difference datetime_expr2 - datetime_expr1 in years, months, days etc. Week where Monday is the first day of the week (01 to 53). The first two arguments, start-date and end-date , are required. , with an example. For VB fans, you can reference the Microsoft. 2 - First day of week is Sunday. MySQL TIMEDIFF () function. When you query data from a DATETIME column, MySQL displays the DATETIME value in the following format: YYYY-MM-DD HH:MM:SS Code language: SQL (Structured Query Language) (sql) By default, DATETIME values range from 1000-01-01 00:00:00 to 9999-12-31 23:59:59. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. e. For example, if we want to know the difference between two dates in seconds: SELECT id, job, TIMESTAMPDIFF(SECOND, start_date, end_date) AS runtime FROM example_table; This calculates end_date - start_date in seconds. Share. dbForge Studio for MySQL. We learned how to get work orders that took longer, get the oldest employees, the time between the. SELECT TIMESTAMPDIFF (MONTH, '2012-05-05', '2012-06-04') -- Outputs. MySQL provides several functions that you can use to perform calculations on dates, for example, to calculate ages or extract parts of dates. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest,. g. Introduction to MySQL DATE_ADD function. Syntax of MySQL DATEDIFF () DATEDIFF (date1, date2) Code language: SQL (Structured Query Language) (sql) Where, ‘date1’ and ‘date2’ are two date or datetime expressions. The MySQL DATEDIFF () function takes two dates and returns the number of days between them. SELECT log, TIMESTAMPDIFF(year, createddate, waitingtime) AS YearDiff, TIMESTAMPDIFF(month, createddate, waitingtime) AS. This will not be accurate. The integer value represents the day and the fractional value represents the. October 10, 2023. mysql> SELECT. SELECT DATEDIFF (dd,0,GETDATE ()) = 40234. TIMESTAMP () With a single argument, this function returns the date or datetime expression. See the following example:Try the below SQL QUERY for finding Year difference between two dates using DATEDIFF function. Discussion: To calculate the difference between the timestamps in MySQL, use the TIMESTAMPDIFF(unit, start, end) function. 1. For example, I don't even remember if MySQL has the BIT datatype. The time value can represent elapsed time as well. 2) perform the differencing in SQL rather than in R so that a "difftime" column is not created in the first place: DF2 <- data. It uses the. TIMESTAMPDIFF () This function subtracts an interval from a datetime expression. mysql> SELECT DATE('2005-08-28 01:02:03'); -> '2005-08-28'. Improve this answer. MySQL is widely used in web applications, content management systems, and data warehousing. The YRDIF function can compute a person’s age. You are not following the example from the Carbon Documentation. Where a time stamp is a numerical value representing the number of milliseconds from '1970-01-01 00:00:01' UTC (epoch) to the specified time. If you're using Unix Timestamp (integer), then it would be even easier: select * from MyTab T where UNIX_TIMESTAMP () - T. YEARWEEK () function in MySQL is used to find year and week for a given date. I strongly recommend you change this; it slows down any date computations you want to do and you risk invalid date values getting entered into the column. answered Nov 8, 2015 at 10:51. Connect and share knowledge within a single location that is structured and easy to search. Difference between OLTP and Inmon Data Warehouse. SQL 2022-03-27 19:30:32 concat column value of same user in mysql SQL 2022-03-27 19:05:02 sql developer sql worksheet not showing SQL 2022-03-27 18:45:07 kill a pid redshiftLearn the syntax of the datediff function of the SQL language in Databricks SQL and Databricks Runtime. is_leap_year else 365 def num_years (start_date:. The first date is the later and the second is the earlier date (flipping them the other way around will return. When analyzing historical data, DATEDIFF () helps quantify the time. MySQL provides a set of functions to. 0000000', @enddate datetime2 = '2016-12-31 23:59:59. WARNING: An ideal function would be aware of leap years and days count in every month, but I found the. Syntax. com. Brilliant. checkdate; date_ add; date_ create_ from_ formatHere's my example statement select (datediff(n, '6/1/2008 10:00:00 AM', '6/2/2008 10:10:00 AM')/60) it should be 24. Any dates entered with a year value less than or equal to the cutoff year are considered to be in the current century, while those greater. We would use the same transaction to debit ACC1 and credit ACC2 with a fund of $100. This can be the name of a date/datetime/timestamp column or an expression returning one of those data types. this will be add to 1900-01-01 , but only the months. The format to use. Here's what that query would look like in Navicat: To convert the rental_date from a datetime to a pure date we can use the DATE () function. def num_days_in_year (date: pd. I want the difference between the times to display something like: 1d 2h 23m. SSS, which is not the case with your date. Takes three arguments, the start date. startdate and enddate have to be in a format. checkdate; date_ add; date_ create_ from_ formatSelect * from employee where e_name LIKE 'j%'; After writing the query, click on the execute button to check for errors. Second parameter would be the last login time, which is already in the database. It is commonly deployed as part of the LAMP stack (which stands for Linux, Apache, MySQL, and PHP) and, as of this writing, is the most popular open-source database in the world. 0. Here’s the syntax of the PERIOD_DIFF () function: PERIOD_DIFF (P1, P2) Code language: SQL (Structured Query Language) (sql) In this syntax: P1: The first period (in the format. Date manipulation is done using the builtin date/time functions, which know how to convert inputs from the other formats. P1 and P2 should be in the format YYMM or YYYYMM. And you are trying to pass a formatted date string. You can just subtract datetimes and it will return the value: select (now () - interval 2 day) - (now () - interval 5 day); The result isn't a datetime (it's some decimal coded date -- 3000000 for three days in this case), but it isn't correct to say consider a datetime and an interval as the same datatype. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part '00:00:00' where necessary. Follow answered Dec 1, 2009 at 21:26. MySQL Examples MySQL Examples MySQL Editor MySQL Quiz MySQL Exercises MySQL Certificate. frame (now, now2) sqldf ("select now2 - now as dif from DF2. 何かとデータが必要になる時に、日付指定とかと格闘することとなると思います。 少なくとも私は、毎度忘れては調べの繰り返しでした。 少しでも誰かのお役に立てたら幸いです。Discussion: To count the difference between dates, use the JULIANDAY() function, which counts the number of days since noon in Greenwich on November 24, 4714 B. MySQL is free and open-source. The MySQL DATEDIFF function is used to get the difference in days between two date values. Date Interval Calculation: The number of specified date parts between two provided dates is found using the DATEDIFF () method. Since all dates will now be saved. 17. I believe that I will need to do something along the lines of. You use MySQL DATETIME to store a value that contains both date and time. SELECT start_time ,end_time ,DATEDIFF(end_time, start_time) ASMySQL Database: Restore Database. QlikView date and time functions are used to transform and convert date and time values. 1. If the date is NULL, the YEAR () function returns NULL. DATE_ADD. Here is an example that uses date functions. Functions are based on a date-time serial number that equals the number of days since December 30, 1899. MySQL is. 0. In MySql the syntax of DATEDIFF is different: DATEDIFF (date1, date2) and returns the difference date1 - date2 in days. SubscrpEndDate__c) AS 'SubscriptionDueDate' According to the manual: DATEDIFF(expr1, expr2) returns expr1 − expr2 expressed as a value in days from one date to the other. When we have two Ys, then the last two digits of the year. For example, if you want to calculate the number of hours between two times, you can use the following SQL query: SELECT DATEDIFF (hour, '2022-01-01 12:00:00', '2022-01-01 14:30:00') AS HourDiff; This query will return the number of hours between 12:00 PM and 2:30 PM on January 1, 2022, which is 2. g. 7 Date and Time Functions. We will use the below date for the examples.