Rest days that are not consecutive — so the week has two short runs, not one.
A split weekend is a rest pattern where the days off are not adjacent: a mid-week rest day and a single weekend day, rather than two together. It occurs where a six-day trading week is normal, in shift and rota work, and in sectors that must open on the conventional weekend.
It breaks an assumption most scheduling code makes without noticing: that a week contains one continuous run of working days. With a split rest pattern there are two shorter runs, and a window search looking for four consecutive clear days will report none where a human would see two comfortable options.
It also breaks the complement between weekend and working week, since neither is a single block.
A weekend implies consecutive days. A split weekend is the case where the rest days are separated, which the word weekend cannot describe.
The rest days are the same objects. Split describes their arrangement — that they do not sit together.
See also weekend · rest day · working week · long weekend
The schema can hold a split pattern because rest days are recorded as a list rather than a range. No jurisdiction in the corpus currently has one evidenced. See what we hold.