Grand time to go on holiday? (6)
I believe the answer is:
august
I believe this clue is a double definition.
'grand' is the first definition.
(august can mean grand or majestic)
'time to go on holiday?' is the second definition.
(time for a summer holiday)
(Other definitions for august that I've seen before include "Revered" , "Gregorian calendar month" , "there's not much of it left now [27 AUGUST]" , "could get sunburned this time of year!" , "Sublime" .)