compensatory holiday; substitute day off
A day off given in exchange for working on a scheduled day off, such as a weekend or public holiday. Often used in workplace contexts.
See also: 代休 (だいきゅう)
Since I worked on Sunday, Monday became my compensatory holiday.
代休 is a more common and general term for a compensatory day off, while 代替休日 is a more formal or specific term often used in official schedules or labor regulations.
Compound of 代替 (substitute, alternative) and 休日 (holiday, day off).