Split shift
A split shift is two separate blocks of work on the same day with a long gap between them, instead of one continuous stretch. A lunch service and a dinner service worked by the same person is the usual example.
Why it matters in a small workplace
A split day is harder on the person working it than the hours on it suggest, and it is easy to create by accident when the two services are scheduled as two separate jobs.
How Weeksort handles it
Weeksort has no special object for it: a split day is simply two shifts on one date, each drawn to the minute. Both count towards the person's hours for that day, and the rest rule is measured across the gap like any other.