DATEDIFF() is a function found in SQL Server and MySQL that calculates and returns the difference between two date values. DATEDIFF function returns the difference of the specified datepart between the two dates (start date and end date). The travel table looks like this:. The syntax for the DATEDIFF function is as follows: DATEDIFF(datepart, startdate, enddate)All datediff() does is compute the number of period boundaries crossed between two dates. 671'), 0), 114) to output 26:11:20:000 but instead it output 02:11:20:000. Elasticsearch SQL accepts also the plural for each time unit (e. #1582 - Incorrect parameter count in the call to native function 'DATEDIFF'. In this case, the enddate is arrival and the startdate is departure. The next example will show the differences between two dates for each specific datapart and abbreviation. Covering popular subjects like HTML, CSS, JavaScript,. 6 Answers. MySQL の TIMEDIFF () は日時や時間型の値を二つ、入力引数として受け取り、その差分の時間を返す日付関数です。. You end up with. 入力引数を datetime で指定すると、日付の部分も考慮して時間の差分が計算されます. Assuming all of your data is "good" (any bad data can get in there when you use the wrong data type), this should work without any conversions. ), the start date or time that specifies the beginning of the period. I prefer this method because it is easier to. 2 Answers. 9. DateTime startDate =. Example #1 – Calculating Age. In case you use a DATE value, the TIMESTAMPDIFF function treats it as a DATETIME value whose time part is. timediff() 以下のような結果なので使えそうだけど、結果から「60 より大きい」を取得するには更に変換が必要そうHi All, I have two date Suppose one is getdate() and other one is gatedate() +1 . The function counts whole elapsed units based on UTC with a DAY being 86400 seconds. Description. hàm datediff. I) if you need to calculate the elapsed time in seconds between two timestamp columns try this: SELECT extract ( day from (end_timestamp - start_timestamp) )*86400 + extract ( hour from (end_timestamp - start_timestamp) )*3600 + extract ( minute from (end_timestamp - start_timestamp) )*60 + extract ( second from (end_timestamp - start. October 10, 2023. g. Something like: SELECT DATEDIFF (d, StartDate, EndDate) FROM tableName. sql; google-bigquery; datediff; date-difference; Share. October 10, 2023. Follow edited May 15, 2018 at 17:24. Syntax TIMEDIFF( <date_or_time_part> , <date_or_time_expr1> , <date_or time_expr2> ) Arguments date_or_time_part The unit of time. Hallo All, I want to find the difference between two order dates, which have the order numbers 3 and 1 and write it to another column (named fark) for each Cust_id. If you want the difference in seconds, use datediff (): select username, avg (datediff (ss, start_date, end_date)) as avg_seconds. 2. Following is the syntax of the above function – TIMEDIFF(expr1, expr2) Example 1 DATEDIFF returns the total number of the specified unit between startdate and enddate. Calculating the difference between two dates or times in DB2. Must be one of the values listed in Supported Date and Time Parts (e. numeric-expression. For an overview of all Transact-SQL date and time data types and functions, see Date and Time Data Types and Functions (Transact-SQL). TIME_TO_SEC (TIMEDIFF (endDate, startDate))/3600 as hours. example, if start_date and end_date differed by 59 seconds, then DATEDIFF(MINUTE, start_date, end_date) / 60. Given a unit of SECOND, TIMESTAMPDIFF() is a more robust solution. datediff. DateDiff of 2 dates in the same column SQL. CTE works wonder in such scenarios. you ca also use LAG analytical function to get the desired results as : Suppose below is your input table: id account_number account_date 1 1001 9/10/2011 2 2001 9/1/2011 3 2001 9/3/2011 4 1001 9/12/2011 5 3001 9/18/2011 6 1001 9/20/2011 select id,account_number,account_date, datediff(day,lag(account_date,1) over (partition by account_number order by account_date asc),account_date) as day. Edit the SQL Statement, and click "Run SQL" to see the result. Thuộc về danh mục hàm Date. To get the difference in. SQL Server: -- Difference between Oct 02, 2011 and Jan 01, 2012 in years SELECT DATEDIFF (year, '2011-10-02', '2012-01-01'); -- Result: 1. The first number you see is the number of whole days that passed from departure to arrival. sqlserver. UserID = Users. 12:25 occurred with 12 minutes and 25 seconds left, etc. MS Sql Datediff Function. So I would return 0. I need to use timediff function in where clause. For example, you can use: SELECT TIMESTAMPDIFF (SECOND, '2012-06-06 13:13:55', '2012-06-06 15:20:18') In your case, the third parameter of TIMSTAMPDIFF function would be the current login time ( NOW () ). DECLARE @null time; SET @null = '00:00:00'; SELECT DATEADD(SECOND, - DATEDIFF(SECOND, End_Time, Start_Time), @null) Reference: Time Difference Edit: As per the comment, if the difference between the end time and the start time might be negative, then you need to use a case statement as suchDescription. 0. ORDER BY DATEDIFF(endDate, starDate), TIMEDIFF(TIME(endDate), TIME(starDate)); Probably performs terribly, though. The T-SQL DATEDIFF is defined as a primary function in T-SQL that can be used to find the difference between two date-utilities in which it has been utilized to differentiate between two date values having various date parts. DateDiff (String, Nullable<DateTime>, Nullable<DateTimeOffset>) Returns the count of the specified datepart boundaries crossed between the specified start date and end date. SQL Server DATEDIFF() 日期相減. The second parameter of DATEDIFF takes a datetime so your string is implicitly converted to a datetime. The SQL DATEDIFF function is a built-in function in SQL that calculates the difference between two dates or times. That prevents SQL Server from using. mysql Timediff() function returns 0. You don't specify the granularity you want for the diff. According to DB2's manual, DAYS () returns: "The result is 1 more than the number of days from January 1, 0001". 677', '2021-02-17 20:52:51. 0. If you need the number of fractional hours, you can use DATEDIFF at a higher resolution and divide the result: DATEDIFF(second, start_date, end_date) / 3600. To compare dates in SQL, the most common functions used are DATEDIFF, DATE_ADD, DATE_SUB, and NOW. just substitute StartDate and EndDate for your column names, and tableName for the actual table name. To do so, we can utilize the timestampdiff () function provided by DB2. SQL Server: -- Get difference in days SELECT DATEDIFF(dd, '2022-09-01', '2022-09-05'); # 4By default, MySQL TIME fields allow a time range of '-838:59:59' to '838:59:59'. Hàm DATEDIFF SQL Server có những đặc điểm nổi bật sau: Được dùng để tìm sự khác biệt giữa hai ngày tháng. If you want the difference in seconds, use datediff (): select username, avg (datediff (ss, start_date, end_date)) as avg_seconds. One month is considered elapsed when the calendar month has increased and the calendar day and time is equal or greater to the start. SELECT DATEADD (month, 1, '20220730'); The below DATEADD will add 1 year to the provided date value, the year changed from 2022 to 2023. 0. @Bruno - If the data types are TIMESTAMP WITH TIME ZONE, the interval that results from subtracting the two should take care of any time zone/ daylight savings time conversion. USER_FECHA_INCORPORACION, AGENTE. WITH Calc AS ( SELECT S. Mangu. If the returned result is out of range for 32-bit. 1 = Sunday (this is default) 2 = Monday. Run SQL ». startdate), MAX(t. Datetime2 Overflow Issue-1. answered Aug 1, 2014 at 6:27. The int data type takes 4 bytes as storage size whereas bigint. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. In addition, with DATEDIFF () the column is an argument to the function. @asfasas You can always convert the results using a proper mask. Edit the SQL Statement, and click "Run SQL" to see the result. This means. functions. Requires 3 arguments. Few examples of DATEDIFF: DATEDIFF - Example 1 Here, in this example, datepart is "day": SELECT DATEDIFF(day,'2016-06-05','2016-08-05') AS DiffDate. In this article: Syntax. DateDiff to show Minutes and Seconds. DATEDIFF – Name of function. Getting Hour and minute in from DATEDIFF in decmial format, SQL. 27' which means 270ms rather than 27ms. Bohemian ♦. If you want hour to be very specific, you can use as given below: Declare @Start DateTime = '1/1/17 7:59 AM' Declare @End Datetime = '1/1/17 8:00 AM' select DATEDIFF (MINUTE, @Start, @end) /60 AS Hour. 0 and above Returns the difference between two timestamps measured in units. La función DATEDIFF() en SQL devuelve la diferencia entre dos fechas. Timestamp difference in PySpark can be calculated by using 1) unix_timestamp () to get the Time in seconds and subtract with other time to get the seconds 2) Cast TimestampType column to LongType and subtract two long values to get the difference in seconds, divide it by 60 to. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. First, here’s the syntax: DATEDIFF(expr1,expr2) Where expr1 is the first date,. This function is a synonym for timestampdiff function. Factor by 24 to get hours, 24*60 to get minutes, 24*60*60 to get seconds (that's as small as dates go). The difference is measured in the time unit specified by datepart. An INTEGER. DateValue > DateAdd (day,-3,getdate ()) doing this in this way makes your. SQL Server DATEDIFF Function Summary: in this tutorial, you will learn how to use SQL Server DATEDIFF () function to calculate the number of years, months, weeks, days,etc. datediff¶ pyspark. enddate: The ending datetime value. Spudley. event =. How to compare two dates ignoring seconds in sql server. I have the following conditional statement in my SQL query: WHERE TIMEDIFF("03:00:00", VARIABLE) >= "00:05:00" The above works as expected. 9. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type. 0 . Return the difference between two time expressions: SELECT TIMEDIFF ("13:10:11", "13:10:10"); Try it Yourself » Definition and Usage The TIMEDIFF () function returns the difference between two time/datetime expressions. SQL Server provides several built-in functions to calculate the difference between dates. To count the difference between dates in MySQL, use the DATEDIFF (enddate, startdate) function. If TIMEDIFF() returns -02:00:00, -00:05:00, or 00:04:00, then the record would. To achieve this, we will utilize the MySQL DATEDIFF () function to calculate their ages: SELECT CONCAT (first_name, ' ', last_name) AS full_name, birth_date, FLOOR (DATEDIFF (CURRENT_DATE, birth_date) / 365) AS age FROM employees; In this query, the DATEDIFF () function calculates the number of days between the current date and. In this article, Let us see a Spark SQL Dataframe example of how to calculate a Datediff between two dates in seconds, minutes, hours, days, and months using Scala language and functions like datediff(), unix_timestamp(), to_timestamp(), months_between(). Now let us go to next question regarding difference between GETDATE and CURRENT_TIMESTAMP. datediff¶ pyspark. The following shows the syntax of the DATEPART() function:. learn sql tutorial. Diff the minutes, then divide to get days)SQL Sever - Datediff, hours, but exclude Saturday/ Sundays. Hot Network Questions Using Parseval's to Evaluate an Integral Energetic man and his boisterous son are a better fit as colonists than on an overcrowded Earth Take BOSS to a SHOW, but. How to calculate age in SQL view. This does it in days: select username, avg (end_date - start_date) as avg_days from mytable group by username. That will give you the average differences for each distinct value of col1. Like the two fields are sale_start_date. The DATETIME system is newer (but still old — circa 1990). It accepts any valid date or datetime expression. 如需處理 startdate 與 enddate 值之間較大差異的函式，請參閱 DATEDIFF_BIG. Timediff in MySQL wrong values. The default column name for the DATEDIFF function is DATE_DIFF. 3 and above. CreatedDate, DATEDIFF (DAY, a1. Q&A for work. 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. its a countdown with the current date. The number of days is calculated using the MySQL DATEDIFF () function. SQL Command Syntax; SQL Commands List; SQL Functions List; Comparison Operators and Functions. I used your SQL Fiddle and posted a working solution here. There's no built-in function - but you could relatively easily write your own T-SQL stored function to calculate this - something like this: CREATE FUNCTION. startdate: The starting datetime value. If you need the difference in seconds (i. to get the date one second before midnight of. Column [source] ¶ Returns the number. MySQL timediff on one column for selected records in table. selectExpr (" (unix_timestamp (ts1) - unix_timestamp (ts2))/3600") This first converts the data in the columns to a unix timestamp in seconds, subtracts them and then converts the difference to hours. 1 Answer. How can i perform this directly in my sql without scheduling events?DATEDIFF function. Sintaxis. First, a quick example of turning a "number of seconds" into the "hh:mm:ss" format. date_or_time_expr1, date_or_time_expr2 W3Schools offers free online tutorials, references and exercises in all the major languages of the web. sql timediff function. It is the unit in which the DATEDIFF () function returns the difference between a start date and an end date e. SELECT DATEDIFF (YY,'01/02/2011 15:00:00','01/01/2016 14:00:00') 5. So, we can use the TIMEDIFF() function with time values greater than 24 hours. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. . Sql server supports adding and subtracting on Datetime data type, so you can simply do something like this: DECLARE @StartTime datetime = '2016-05-10 02:25:34. 0. Invalid function type [DATEDIFF] for window function. For example, the number of minutes between two datetime values evaluates the date component as well as the time component, and adds 1440 minutes for each day difference. SELECT id, timeIn, timeOut, TIMEDIFF( timeOut, timeIn ) AS timeDifference FROM table WHERE TIMESTAMPDIFF( SECOND, timeOut, timeIn ) > 180000; This. Run SQL ». 1. SELECT id, timeIn, timeOut, TIMEDIFF ( timeOut, timeIn ) AS timeDifference FROM table WHERE TIMESTAMPDIFF ( SECOND, timeOut, timeIn ) > 180000; This statement will output the fields for each record where the difference between the two timedates is one second or more over 50 hours (or 180000 seconds ). Datediff with join returning not expected result. function. 000 FirstCall = 2012-02-29 12:12:19. Use DATEDIFF(DAY, column, GETDATE()). This is a very old question and your answer doesn't really answer the same. The datepart argument defines the part of the date/datetime in which you'd like to express the difference. select post_visid_high || ':' || post_visid_low as visitor_id , lag (date_time) over (partition by visitor_id order by date_time asc) as previous_date , datediff (minute, previous_date, date_time) as difference_in_minutes from adobe_data. This example uses the DateDiff function to display the number of days between a given date and today. x) and later Azure SQL Database Azure SQL Managed Instance This function returns the count (as a signed big integer value) of the specified datepart boundaries crossed between the specified startdate and enddate. You obtain this record using the LAG () window function. Date DateAdd DateDiff DatePart DateSerial DateValue Day Format Hour Minute Month MonthName Now Second Time TimeSerial TimeValue Weekday. TIMEDIFF () returns expr1 - expr2 expressed as a time value. Also stop using lazy shorthand like DATE1 - DATE2 (it doesn't work with the data types you should be using since SQL Server 2008). Need to find the datediff between more then two dates. 33 shows the available functions for date/time value processing, with details appearing in the following subsections. Here, you'd like to get the difference in seconds, so choose second. 1. 000', @EndTime datetime = '2016-05-10 03:31:00. Abbrevations. DatePart. Note: TIMEDIFF () requires two arguments for comparison, and TIMEDIFF () subtracts the second argument from the first, then returns the result as the time value. DateGroup. This function allows you to obtain data from the previous record (based on an order criterion, which here is “ ORDER BY year ”). orderno, datediff(day, op1. date1, date2: a valid time, datetime, or parsable time/datetime string. The following illustrates the syntax of the DATEDIFF () function in SQL Server:. 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. Edit the SQL Statement, and click "Run SQL" to see the result. SQL Server Syntax DATEDIFF(datePart, date1, date2) The DATEDIFF() function in SQL Server has three required parameters:. The datepart argument can be microsecond, second, minute, hour, day, week, month, quarter, or year. Table 9. Hope it helps. Note that unit values can be different in SQL Server DATEDIFF and MySQL TIMESTAMPDIFF. The syntax for DATEDIFF is pretty straightforward: DATEDIFF (datepart, startdate, enddate) Let’s explore the parameters used here: datepart: The unit of time you want to use for the calculation, like year, quarter, month, day, or even smaller units like hour, minute, or second. UserID ORDER BY Feeds. See more linked questions. It is better to keep dates as dates (e. If you want to your query to return three (one for each actual date involved), either JOIN to a calendar table, add one to the result automatically, or do the datediff in hours, divide by 24. g. 0 would return 0, but DATEDIFF(second, start_date, end_date) / 3600. One practical example of using the DATEDIFF function in SQL Server is in a WHERE clause by selecting all employees in the AdventureWorks2008R2 database whose date of hire was in March 2003. This code snippet shows how to calculate time differences. Share. Also, you can swap out the 'd' character for other dateparts, say if you wanted to find the date difference in months, years etc. Multiply by 24 -- hours, multiply by 60 minutes, multiply by 60 -- seconds. All of this is well documented in MySQL Date and Time functions. SELECT DATEDIFF (day, '2019-12-05 08:09:55', GETDATE ()); Result: 39. Here is my existing SQL statement: SELECT TOP 10 Users. SQL Server added the LAG and LEAD functions in T-SQL to help find a previous record related to the key fields. startdate: The first date or datetime value. The syntax is: DATEDIFF ( datepart , startdate , enddate ) For parameter datepart, refer to the following table: Datepart. 0 and above. Select idcode, datetime, Difference = datediff (millisecond,. How to make the result in date format using datediff btween 2 columns. From second to datetime sql server. The MYSQL TIMEDIFF() function accepts two time or, date-time values as parameters, calculates the difference between them (argument1-argument2) and returns the result. These functions assist in comparing, adding, subtracting, and getting the current date and time, respectively. The datepart argument can be microsecond, second, minute, hour, day, week, month, quarter, or year. Teams. 更多 SQL Server 相關的日期時間函數在這邊. You can even find the number of hours, minutes, seconds, and so on in terms of details in between the two. The part can be the day of the date, month of the date, year of the date etc. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. timediff. T-SQL DATEDIFF returns Years and Month. Where @startDate and @endDate are today's date at 00:00:00 and 11:59:59. The DATEPART () function returns an integer value that represents a specified part of the date of a given date. 0. The DATETIME system is newer (but still old — circa 1990). 0000000' , '2014-03-19 07:20:00. The functions in this section use a format string that is compatible with JodaTime’s DateTimeFormat pattern format. The format of the timediff() result is designed to be human-readable. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. ). The following. sql. DATEDIFF( date_part , start_date , end_date) Code language: SQL (Structured Query Language) (sql) The DATEDIFF() function accepts three arguments: date_part , start_date , and end_date . DATEDIFF() returns (expr1 – expr2) expressed as a value in days from one date to the other. DATEDIFF (MONTH, DATEADD (DAY,-DAY (startDate)+1,startDate),DATEADD (DAY,-DAY (startDate)+1,endDate)) Share. The best will likely be: SELECT <column list> -- not * (1) FROM dbo. Must be one of the values listed in. In this, we will add the number of years that we expect this person to turn in a given year, based on the DATEDIFF( ) results. However I see two disadvantages with this method. Timestamp = DATEDIFF (MINUTE, Feeds. Get date difference. Query to Find the date difference between 2 rows of a single column. sql. The TIMESTAMPDIFF function returns an estimated number of intervals of the type that is defined by the first argument, based on the difference between two timestamps. It returns an integer value that represents the number of specified date or time units between two dates or times. Bid DESC ) AS T ) SELECT Pair, AVG(DIFF) FROM. Follow answered Apr 1, 2015 at 14:05. That is a 5 hour difference. This function accepts three parameters − the type of interval to measure (such as year, quarter, month, hour, minute, etc. This function accepts three parameters − the type of interval to measure (such as year, quarter, month, hour, minute, etc. SQL Server DATEDIFF function returns the difference in seconds, minutes, hours, days, weeks, months, quarters and years between 2 datetime values. select datediff (qtr, '1998-07-01', current_date); date_diff ----------- 40 (1 row) The following example joins the SALES and LISTING tables to calculate how many days after they were listed any tickets were sold for listings 1000 through 1005. DATESUB (date_string, amount, 'unit') Subtracts a time interval from a date or datetime. Passing DATEDIFF interval as user defined function argument?I came across an easier way of solving this issue. DateDiff to find duration in minutes not working. Hopefully this gets you pointed in the right direction! Thanks for response Eric TIMEDIFF also gives me time difference. (For more information about how DateDiff() works see DATEDIFF Function Demystified. DATEDIFF uses the following cutoff points to calculate those intervals:. The unit argument can be MICROSECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR. The schema is SYSIBM. Description. Note that SQL Server DATEDIFF function returned 1 year although there are only 3 months between dates. mySql TimeDiff between TimeStamp in Rows of a Single Table. Date Part Intervals. All you need is to execute the code below and then use the function. The next example will show the differences between two dates for each specific datapart and abbreviation. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Run SQL ». DatePart. How to find time in seconds between two cross columns in SQL Server. Pair = s. SELECT *, ISNULL(DATEDIFF(mi, LAG(CreateDate,1) OVER (ORDER BY ID), CreateDate), 0) AS Duration. Cú pháp sử dụng hàm DATEDIFF () Hàm DATEDIFF () được sử dụng để kiểm tra sự khác biệt giữa hai khoảng thời gian, cú pháp của hàm DATEDIFF () như sau: DATEDIFF(interval, date1, date2) Tham số: interval là khoảng sử dụng. I have to show the difference, currently I used a datediff in the stored proc which just shows the difference of the days :( but i need to show the difference in days:hours:minutes:seconds if possible. datepart 値を変数に指定することはできません。 また、'month' のように引用符で囲まれた文字列として指定することもできません。STEP 1: Calculate the difference between the Order date and Ship date to know how long it took. Returns the difference between two timestamps measured in unit s. YEAR. The addition of these functions help with readability and simplicity. The DATE type is oldest (it was in the precursor to the SQL-based Informix), and represents the integer number of days since a reference date (where day 0 is 1899-12-31, so day 1 was 1900-01-01). Number of weekdays between two dates - StartDate question. 8. 0. column. LogDesc, Feeds. That prevents. . To do this, we need to create a calculated column using the DATEDIFF DAX function as seen in the diagram and DAX syntax below. 1. Learn more about TeamsDateDiff (String, Nullable<DateTime>, Nullable<TimeSpan>) Returns the count of the specified datepart boundaries crossed between the specified start date and end date. Datediff returns the number of borders passed between one value and another; in the case of days, think of the function as counting midnights. Using timestamp column value in TIMEDIFF function. If start is greater than end the result is negative. An expression that returns a value that is a built-in SMALLINT or INTEGER data type. To convert “Datetime” values to Epoch values, we need to add them to the created table. The solution is to use the DATEDIFF () function. Note: As TT rightfully wrote in his comment,. order_logs_created, DATEDIFF (HOUR ,NOW (),order_logs. Just in case you didn't understand the other answers, you can use DATEDIFF. SQL> select 24 * (to_date ('2009-07-07 22:00', 'YYYY-MM-DD hh24:mi') - to_date ('2009-07-07 19:30', 'YYYY-MM-DD hh24:mi')) diff_hours from dual;. Find the interval between today's date and a column. Applies to: Databricks SQL Databricks Runtime 14. . DATEDIFF returns the count of the specified date part boundaries crossed between. 0. 1 (for Linux, Unix and Windows) and above, this will work. The TIMEDIFF() function returns the difference between two TIME values (time1 - time2) in the format 'HH:MM:SS'. The function returns an INTEGER value representing the number of intervals between the two timestamps. Update2. Syntax TIMEDIFF( <date_or_time_part> , <date_or_time_expr1> , <date_or time_expr2> ) Arguments date_or_time_part The unit of time. 4. Table 9. So subtracting a TIMESTAMP WITH TIME ZONE that is 5 am Eastern from a TIMESTAMP WITH TIME ZONE that is 2 am Pacific will result in an interval of 0. DATEDIFF is an date function and returns the count of the specified date_part boundaries crossed between twoo specified dates: start_date and end_date. 1. ID. DATEDIFF(hour, start_date, end_date) will give you the number of hour boundaries crossed between start_date and end_date. In the end, you typically see these calculations done with code. OR LOWER(CAST( "DATEDIFF(month, USER. SQL Server does not. Relational databases store information in table cells — in columns that describe aspects of an item and rows which tie together the columns. 4 = Wednesday. DATE_ADD () Add time values (intervals) to a date value. This function takes the difference between two dates and shows it in a date format yyyy-mm-dd. The SQL DATEDIFF function calculates and returns the difference between two date values. Also, you can swap out the 'd' character for other dateparts, say if you wanted to find the date difference in months, years etc. Timediff in MySQL wrong values. datePart is the part of the date to return. You'll get a more accurate result if you compute the difference between the two dates in days and divide by the mean length of a calendar year in days over a 400 year span (365. DATE_SUB () Subtract a time value (interval) from a date. sql.