A split shift is two segments with a gap that is not a break and is not working time. Spreadsheets handle it badly because they store a first punch and a last punch, so the unpaid middle disappears into the total.
Record segments, not a day
If the roster holds the segments, each punch can be matched to the segment it belongs to. Scheduled, worked, late and overtime are then separable — which is what makes the overtime figure defensible.
Watch the midnight rollover
Shifts that cross midnight are where most manual calculations silently fail. The hours land on the wrong day, and in the wrong month when the shift crosses month-end.