You should schedule your check-ins to be sent at times you're most likely to be able to respond to them.
You'll want to make sure these are times that you are typically awake and have your phone close by. Most users schedule their check-ins during the morning or in the early evenings.
Some users disable their check-ins during weekends as their schedules may be less routine.
While you have an hour (or more, if you choose) to respond to your check-ins, you'll want to carefully choose your check-in schedule as to not needlessly alarm your emergency contacts should you fail to respond for non-emergent reasons.