In Menu > Settings > Notifications > Reminders you're given two options: Calendar and Run-Time. Let's say you want to have Filter 1 Reminder set to 3 months. With Calendar Time, it will take 3 months regardless of whether the system is running or not for the reminder to show. With Run-Time, it will take 3 months of the system running (which may be longer than 3 calendar months) for the reminder to show.
For more information or a visual representation of steps please reference our user guide here
