The Two-Part Rule for Ghusl Time
With respect to a woman's established menses habit, there are two distinct scenarios that determine whether ghusl time becomes part of the recorded habit:
Before the 10-Day Maximum
If menstrual bleeding ends before the maximum of 10 complete days (240 hours), the ghusl time is added to the menses habit. This means the woman remains in a state of menstruation until she performs ghusl, provided the maximum limit has not been reached.
At the 10-Day Maximum
If menstrual bleeding ends exactly at the 10-day maximum (240 hours), the ghusl time is not added to the menses habit. Once the maximum limit is reached, menstruation officially ends regardless of whether ghusl has been performed.