A worker starts at 22:00 on Tuesday and finishes at 06:00 on Wednesday. They have worked one shift.
Record it against calendar dates and you get two entries of four hours each: a half day on Tuesday and a half day on Wednesday. Neither is true, and everything computed from them is wrong.
What breaks
Payable days. Two half days may total one, but the employee sees two half-day entries in a register that is supposed to show what they did.
Overtime. Overtime is computed against the shift's normal hours. Split the shift and there are two partial shifts, neither of which exceeds anything, so genuine overtime disappears — or appears in the wrong place.
Weekly off. A shift beginning on Saturday night and ending Sunday morning may look like Sunday working when it is not, which triggers comp-off or double-rate calculations that were never earned.
The register. Any document produced from this shows a night workforce as permanently half-present, which is exactly the sort of thing that draws a question during an inspection.
In some industries it is the ordinary case
Manufacturing, logistics, healthcare and hospitality do not have occasional night shifts. They have night shifts as a standing pattern, covering a substantial part of the workforce.
Treating cross-midnight as an edge case to be worked around is therefore a decision to work around the majority of your attendance data.
The rule to configure
A shift belongs to the day it starts. Once that is set, everything downstream resolves: the day counts once, overtime computes against the full shift, the weekly off falls where it should, and the register reads as the month actually happened.
Check it in five minutes
Find a night-shift employee and open last month's attendance. If they show as present on more days than they worked, at half a day each, you have it.
It is worth checking even if you believe it is configured correctly — this is a setting that is frequently right in the shift master and wrong in whatever reads it.
While you are there, check breaks
The other night-shift error is paying overtime across an unpaid break. If the shift includes a canteen break that policy says is unpaid, and overtime is computed on total elapsed time, you are paying a premium rate for it every night.