Get date of monday's previous week


How can I get the date of monday’s previous week using expression functions ?
For exemple, today’s date is 05-oct-2018 15:30. My result should be 29-oct-2018 00:00:00.

I believe you mean today is November 5th, not October. Anyways, try this:

dateArithmetic(dateArithmetic(midnight(now(0)), -(getDayOfWeek(now(0))-2), "day"), -7, "day")

ok it’s working.