moveable feast

Translations
передвижной праздник
Easter is a moveable feast, celebrated on different dates each year.
Пасха - это передвижной праздник, отмечаемый в разные даты каждый год.
Definitions
A moveable feast refers to a celebration or event that does not have a fixed date and can be observed on different days or at different times, often depending on specific circumstances or conditions. The term is also used to describe a meal that can be enjoyed in various locations or settings.