DATEDIFF (SSIS Expression)
Applies to: 
SQL Server
SSIS Integration Runtime in Azure Data Factory
Returns the number of date and time boundaries crossed between two specified dates. The datepart parameter identifies which date and time boundaries to compare.
Syntax
DATEDIFF(datepart, startdate, endate)
Arguments
datepart
Is the parameter that specifies which part of the date to compare and return a value for.
startdate
Is the start date of the interval.
endate
Is the end date of the interval.
Result Types
DT_I4
Remarks
The following table lists the dateparts and abbreviations recognized by the expression evaluator.
| Datepart | Abbreviations |
|---|---|
| Year | yy, yyyy |
| Quarter | qq, q |
| Month | mm, m |
| Dayofyear | dy, y |
| Day | dd, d |
| Week | wk, ww |
| Weekday | dw, w |
| Hour | Hh |
| Minute | mi, n |
| Second | ss, s |
| Millisecond | Ms |
DATEDIFF returns a null result if any argument is null.
A date literal must be explicitly cast to one of the date data types. For more information, see Integration Services Data Types.
An error occurs if a date is not valid, if the date or time unit is not a string, if the start date is not a date, or if the end date is not a date.
If the end date is earlier than the start date, the function returns a negative number. If the start and end dates are equal or fall within the same interval, the function returns zero.
SSIS Expression Examples
This example calculates the number of days between two date literals. If the date is in "mm/dd/yyyy" format, the function returns 7.
DATEDIFF("dd", (DT_DBTIMESTAMP)"8/1/2003", (DT_DBTIMESTAMP)"8/8/2003")
This example returns the number of months between a date literal and the current date.
DATEDIFF("mm", (DT_DBTIMESTAMP)"8/1/2003",GETDATE())
This example returns the number of weeks between the date in the ModifiedDate column and the YearEndDate variable. If YearEndDate has a date data type, no explicit casting is required.
DATEDIFF("Week", ModifiedDate,@YearEndDate)
See Also
DATEADD (SSIS Expression)
DATEPART (SSIS Expression)
DAY (SSIS Expression)
MONTH (SSIS Expression)
YEAR (SSIS Expression)
Functions (SSIS Expression)