SQL window functions provide extremely powerful and useful features that let you work with observations more easily. Different types explained here.

This chapter summarizes the time intervals, date and datetime informats, date and datetime formats, and date and datetime functions available in the SAS system. The use of these features is explained ...

DATEDIFF is a common function in the SQL Server to find the number of days between two dates. Oracle offers its own solution, although does not have the DATEDIFF function.