My weekly screen time report only shows Sunday, on Sunday.

I get my screen time report notification on my iPhone XR running latest iOS 13 every Sunday morning. But it only shows Sunday's time -- which is only a few hours. It seems that the screen time's week starts on Sunday instead of Monday -- which is fine, but shouldn't it notify me on Saturday instead?

I can never see my previous week's time because by the time I get the notification, Monday to Saturday are always empty.