Movable feast British noun phrase informal
A religious holiday that takes place on a different date every year.
Since Easter usually takes place on any Sunday between the end of March and the beginning of April, it is called a movable feast.
Something that can occur at any time or place that people want.
We usually have dinner at 6 P.M, but sometimes it can be a movable feast.
a long time ago
To remain influential in a particular situation or a particular group of people for a long time
Time is running out.
This expression means something will occur in the near future.
Blind man's holiday is the time between daylight and darkness when people cannot work because it is too dark to see.