Niche for a holiday (6)
I believe the answer is:
recess
I believe this clue is a double definition.
'niche' is the first definition.
(I know that niche can be written as recess)
'for a holiday' is the second definition.
(both can mean a break)
(Other definitions for recess that I've seen before include "Holiday period" , "bay" , "Official holiday break" , "Space sent in a wall" , "Closed period for parliament" .)