Tag Archives: DateDiff() function in Sql

Difference between DATEDIFF and DATEDIFF_BIG functions in Sql Server

This article gives an introduction to the DATEDIFF and DATEDIFF_BIG functions by listing out the differences and similarities between them.

[ALSO READ]: How to get difference between two dates in Years, Months and days in Sql Server

DATEDIFF Function DATEDIFF_BIG Function
This function is available from very old versions of Sql Server. This function is introduced in Sql Server 2016
This function returns the number of the specified datepart boundaries crossed between the specified startdate and enddate This function returns the number of the specified datepart boundaries crossed between the specified startdate and enddate
Syntax:
DATEDIFF( datepart, startdate, enddate)

Where datepart can be one of the following values: year, quarter, month, dayofyear, day, week, hour, minute, second, millisecond, microsecond and
nanosecond

Syntax:
DATEDIFF_BIG(datepart,startdate,enddate)

Where datepart can be one of the following values: year, quarter, month, dayofyear, day, week, hour, minute, second, millisecond, microsecond and
nanosecond

This functions return value data type is INT This functions return value data type is BigINT
Example: Below is an example getting difference between two dates in days using DATEDIFF function:

SELECT DATEDIFF(DAY,
 '12/01/2015','12/02/2015')
 AS 'Difference in days'

RESULT:
Difference in days
——————
1

Example: Below is an example getting difference between two dates in days using DATEDIFF_BIG function:

SELECT DATEDIFF_BIG(DAY,
 '12/01/2015','12/02/2015')
  AS 'Difference in days'

RESULT:
Difference in days
——————–
1

Example: This example demonstrates the behavior of the DATEDIFF function when the milliseconds difference between two dates is greater than the INT max (i.e. 2,147,483,647) value.

SELECT DATEDIFF(MILLISECOND,
 '12/01/2015','12/30/2015')
 AS 'Difference in MILLISECOND'

RESULT:

Msg 535, Level 16, State 0, Line 1
The datediff function resulted in an overflow. The number of dateparts separating two date/time instances is too large. Try to use datediff with a less precise datepart.

Example: This example demonstrates the behavior of the DATEDIFF_BIG function when the milliseconds difference between two dates is greater than the INT max (i.e. 2,147,483,647) value.

SELECT DATEDIFF_BIG(MILLISECOND,
 '12/01/2015','12/30/2015') 
AS 'Difference in MILLISECOND'

RESULT:
Difference in MILLISECOND
————————-
2505600000

The minimum and maximum value that this function can return is: -2,147,483,648 and +2,147,483,647 The minimum and maximum value that this function can return is: -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807

ALSO READ

How to get difference between two dates in Years, Months and days in Sql Server

Many a time we come across a scenario where we need to calculate the difference between two dates in Years, Months and days in Sql Server. In this article we will see how we can achieve this. This article covers the following:

  • Difference between two dates in Years
  • Difference between two dates in Months
  • Difference between two dates in Days
  • Difference between two dates in X years Y Months and Z days (For example: Age in Years, Months and days)

1. Difference between two dates in Years

Approach 1:

We can use DATEDIFF() function like below to get the difference between two dates in Years in Sql Server. DATEDIFF() functions first parameter value can be year or yyyy or yy all will return the same result. Below example shows how we can get difference between two dates in Years

DECLARE @FromDate DATETIME = '2014-12-31', 
        @ToDate DATETIME = '2015-01-01'
SELECT @FromDate 'From Date', @ToDate 'To Date',
 DATEDIFF(YEAR, @FromDate, @ToDate)
   -
 (CASE
   WHEN DATEADD(YEAR, 
           DATEDIFF(YEAR, @FromDate,@ToDate), @FromDate)
       > @ToDate THEN 1 
         ELSE 0 END) 'Date difference in Years'

RESULT:
Difference between dates in years

Approach 2:

You may be thinking why such a complex logic is used to calculate the difference between two dates in years in Apporach 1 instead of using just a single DATEDIFF() function. The reason for using such a complex logic is, DATEDIFF() function returns the number of boundaries crossed by the specified datepart between the specified fromdate and enddate. Basically it calculates the difference between two dates by ignoring all the dateparts smaller than the specified datepart from both the dates. Let us understand this with an example

DECLARE @FromDate DATETIME = '2014-12-31', 
        @ToDate DATETIME = '2015-01-01'
SELECT @FromDate 'From Date', @ToDate 'To Date',
 DATEDIFF(YEAR, @FromDate, @ToDate) 'Date difference in Years'

RESULT:
Date Difference in Years using DateDiff function

From the above result it is clear that even-though @ToDate is the next day from the @FromDate, but still the difference returned is 1 year. So based on the need use the appropriate approach. If we need to calculate age, then we should be using the Approach1.

2. Difference between two dates in Months

We can use DATEDIFF() function like below to get the difference between two dates in Months in Sql Server. DATEDIFF() functions first parameter value can be month or mm or m all will return the same result. Below example shows how we can get difference between two dates in Months

DECLARE @FromDate DATETIME = '2014-12-31', 
        @ToDate DATETIME = '2015-01-01'
SELECT @FromDate 'From Date', @ToDate 'To Date',
   (DATEDIFF(MONTH, @FromDate, @ToDate)
   -
   (CASE WHEN DATEADD(MONTH, 
        DATEDIFF(MONTH, @FromDate, @ToDate), @FromDate)
       > @ToDate
     THEN 1 ELSE 0 END)) 'Date difference in Months'

RESULT:
Difference between dates in months

Approach 2:

You may be thinking why such a complex logic is used to calculate the difference between two dates in months in Apporach 1 instead of using just a single DATEDIFF() function. The reason for using such a complex logic is, DATEDIFF() function returns the number of boundaries crossed by the specified datepart between the specified fromdate and enddate. Basically it calculates the difference between two dates by ignoring all the dateparts smaller than the specified datepart from both the dates. Let us understand this with an example

DECLARE @FromDate DATETIME = '2014-12-31', 
        @ToDate DATETIME = '2015-01-01'
SELECT @FromDate 'From Date', @ToDate 'To Date',
 DATEDIFF(MONTH, @FromDate, @ToDate) 'Date difference in Months'

RESULT:
Date Difference in Months using DateDiff function

From the above result it is clear that even-though the @ToDate is the next day from the @FromDate, but still the difference returned is 1 Month. So based on the need use the appropriate approach.

3. Difference between two dates in Days

We can use DATEDIFF() function like below to get the difference between two dates in Years in Sql Server. DATEDIFF() functions first parameter value can be year or yyyy or yy all will return the same result. Below example shows how we can get difference between two dates in Years

DECLARE @FromDate DATETIME = '2015-07-10 23:59:59.000', 
        @ToDate   DATETIME = '2015-07-11 00:00:00.000'
SELECT @FromDate 'From Date', @ToDate 'To Date',
   (DATEDIFF(DAY, @FromDate, @ToDate)
   -
   (CASE WHEN DATEADD(DAY, 
        DATEDIFF(DAY, @FromDate, @ToDate), @FromDate)
       > @ToDate
     THEN 1 ELSE 0 END)) 'Date difference in Days'

RESULT:
Difference between dates in days

Approach 2:

You may be thinking why such a complex logic is used to calculate the difference between two dates in days in Apporach 1 instead of using just a single DATEDIFF() function. The reason for using such a complex logic is, DATEDIFF() function returns the number of boundaries crossed by the specified datepart between the specified fromdate and enddate. Basically it calculates the difference between two dates by ignoring all the dateparts smaller than the specified datepart from both the dates. Let us understand this with an example

DECLARE @FromDate DATETIME = '2015-07-10 23:59:59.000', 
        @ToDate   DATETIME = '2015-07-11 00:00:00.000'
SELECT @FromDate 'From Date', @ToDate 'To Date',
   DATEDIFF(DAY, @FromDate, @ToDate) 'Date difference in Days'

RESULT:
Date Difference in Days using DateDiff function

From the above result it is clear that even-though the @ToDate is the next second from the @FromDate, but still the difference returned is 1 year. So based on the need use the appropriate approach.

4. Difference between two dates in X years Y Months and Z days (For example: Age in Years, Months and days)

We can use a script like below to get the difference between two dates in Years, Months and days.

DECLARE @FromDate DATETIME = '2010-01-01 23:59:59.000', 
        @ToDate   DATETIME = '2015-01-02 00:00:00.000',
        @Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME
SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)
 - (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),
          @FromDate) > @ToDate THEN 1 ELSE 0 END) 

   
SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)
SET @Months =  DATEDIFF(MONTH, @tmpFromDate, @ToDate)
 - (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),
          @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
   
SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)
SET @Days =  DATEDIFF(DAY, @tmpFromDate, @ToDate)
 - (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),
          @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
   
SELECT @FromDate FromDate, @ToDate ToDate, 
       @Years Years,  @Months Months, @Days Days

RESULT:
Difference between dates in years months and days in sql

We can wrap the above script into a scalar function like below and can be reused for calculating the difference between dates

 
CREATE FUNCTION dbo.GetDateDifference
(
   @FromDate DATETIME, @ToDate DATETIME
)
RETURNS NVARCHAR(100)
AS
BEGIN
    DECLARE @Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME
    SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)
     - (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),
              @FromDate) > @ToDate THEN 1 ELSE 0 END) 
   
    SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)
    SET @Months =  DATEDIFF(MONTH, @tmpFromDate, @ToDate)
     - (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),
              @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
   
    SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)
    SET @Days =  DATEDIFF(DAY, @tmpFromDate, @ToDate)
     - (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),
              @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
  
  
    RETURN 'Years: ' + CAST(@Years AS VARCHAR(4)) +
            ' Months: ' + CAST(@Months AS VARCHAR(2)) +
            ' Days: ' + CAST(@Days AS VARCHAR(2)) 
END
GO

Below example shows how we can use the above function in the select statement

DECLARE @FromDate DATETIME = '2010-01-01 23:59:59.000', 
        @ToDate   DATETIME = '2015-01-02 00:00:00.000'
SELECT @FromDate FromDate, @ToDate ToDate, 
       dbo.GetDateDifference(@FromDate, @ToDate) 
           AS 'Difference between dates'

RESULT:
Difference between dates in years months and days by scalar function in sql

We can as-well create a multi-statement table valued function like below to get difference between two dates in years, months and days

CREATE FUNCTION dbo.GetDateDifferenceInYearsMonthsDays
(
    @FromDate DATETIME, @ToDate DATETIME
)
RETURNS
 @DateDifference TABLE (
 YEAR INT,  MONTH INT, DAYS INT)
AS
BEGIN
    DECLARE @Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME
    SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)
     - (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),
              @FromDate) > @ToDate THEN 1 ELSE 0 END) 
   
    SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)
    SET @Months =  DATEDIFF(MONTH, @tmpFromDate, @ToDate)
     - (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),
              @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
   
    SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)
    SET @Days =  DATEDIFF(DAY, @tmpFromDate, @ToDate)
     - (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),
              @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 
   
    INSERT INTO @DateDifference
    VALUES(@Years, @Months, @Days)
   
    RETURN
END

Below example shows how we can use the above function in the select statement

DECLARE @FromDate DATETIME = '2010-01-01 23:59:59.000', 
        @ToDate   DATETIME = '2015-01-02 00:00:00.000'
SELECT * 
FROM dbo.GetDateDifferenceInYearsMonthsDays(@FromDate,@ToDate)
GO

RESULT:
Difference between dates in years months and days by table valued function in sql