I worked in the public library service in Dublin many years ago, and one year, following phone calls to Gay Byrne complaining that the libraries closed for over a week at Christmas. the City Librarian decided to open for 3 days between Christmas and New Year.
Over the 3 days, the branch I worked in issued 32 books in total - 16 customers. The numbers were similar around the city.
The libraries didn't open again between Christmas and New Year during my time there!
One company I worked in kept a record of every day they'd ever been open and business done etc. Therefore they could forcast which days were worth staying open and which days just weren't. Always surprised I haven't seen this kinda of simple record keeping more often. Very few places seem to do it.