Because the rota is planned on Monday and reality happens all week. Somebody swaps, somebody covers, somebody stays two hours late, and none of it reaches the sheet that payroll reads.
At month end the two are reconciled from memory and a group chat, and the version that wins is whoever argues hardest.
Cover and swaps are recorded against the roster as they happen, from a phone, so the rota is a live record rather than a plan. Check-in and check-out produce the hours, and regularisation is a request with an approver rather than an edit.
Split shifts and premiums are part of the pattern rather than manual adjustments at the end.
It does not distribute tronc or calculate service charge allocation — those remain your policy, applied in payroll.
And it will not find you cover. It records the gap immediately and shows who is available and under their hours, which is the part that takes time.
Payroll reads the same record, including the cover and the overtime, so the run is a check rather than a reconstruction. Casual and zero-hours staff are personnel records with their own patterns, not a separate spreadsheet.
Every adjustment keeps its previous value with an actor and a date, which settles disputes in about a minute.
Yes, from the app, with an approver on the change.
Yes, as personnel records with their own working patterns and pro-rated entitlements.
Yes, as part of the pattern rather than as manual adjustments.
Half an hour on your own numbers is usually enough to say whether Nest is the right place to start.