Bedtime discourse is a waste of energy and bandwidth when 4 day work week is an actually viable improvement that could happen in our lifetimes. Dividing our attention between different time-based issues is a surefire way to reduce effectiveness at getting either of them achieved.
Anyway Flexi-Time is already a standard thing used by huge quantities of businesses, it's widely adopted in the UK even by government. It literally eliminates this issue.
Stop talking about bedtimes and start organising to drag your company into giving Flexitime as a concession to workers.