Automatic reminders are used for sending email notifications for users regarding closing and/or approving time reports. They can be set from Administration --> Period categories --> Edit existing period category --> Automatic reminders tab.
Please note that if you don't set up any reminders, no auto-reminding will be done. There isn't any background default logic
You can set multiple reminders for closing/approving time reports with a set logic before/after the last reporting date. for each period category
Once automatic reminders are set, they will be sent out considering the last report date for the current period.
Multiple reminders set on the same day will result in multiple emails being sent out at the same time.
If "0" is set at "days before/after last time reporting day" then the reminder will be sent on the last reporting day.