If I go to bed and to sleep before midnight on any day, my Venu 3 always starts tracking only at midnight when the calendar date changes. So it always shows less than the time I actually slept.
If there no fix for this?
Body Battery isn't using sleep for recharge. It is using stress. Check you body battery graph. It will recharge when the stress is blue (below 25).
So, you can recharge at any time as long as you get low enough stress. It is usually only low enough during sleep so it looks like it is sleep that does the recharging.