idea 38 · build only
Holiday calendar
The closing days that catch visitors out, on a calendar.
English Heritage
The February half-term reprieve inside the winter season is the kind of exception no opening-hours table survives.
https://www.english-heritage.org.uk/visit/Before you travel
When we are shut
Closed all day
Reduced winter hours
Move between months. November through March is marked reduced, with a full week returned in mid February.
The rules are functions, not a hand-typed list of dates, so next year's calendar is already correct. The February exception is coded as an exception, which is the only way that kind of rule survives contact with a real season.