Calculate How Long Activities Take
Use daysBetween() and date_diff() to calculate the difference between two dates or times.
Suppose that you have an opportunity dataset with the account name and the epoch seconds fields:

You want to see how many days ago an opportunity was opened. Use daysBetween() and now(). Use toDate() to convert the order date epoch seconds to a date format that can be passed to daysBetween().
The resulting data stream displays the number of days since the opportunity was opened.

Use date_diff() with datepart = week to calculate how long, in weeks, it took to close each opportunity.
See Also