File group Only check during following times of day ignored

CMK version: 2.1.0p3
**OS version:**Appliance 1.5.2


i have an Error with File group Checking.
We have a public folder which is shared in the entire Company. Every night the folder is cleared and we want to check, if this folder is successfully cleaned. So i set the option for relevant time of day. The problem is, that it`s being checked the entire day and not just in the night.
Error message: