Aspire in turn to be around clubs for long period (5)
I believe the answer is:
epoch
'long period' is the definition.
(I've seen this before)
'aspire in turn to be around clubs' is the wordplay.
'aspire' becomes 'hope' (I've seen this in another clue).
'in turn' says the letters should be written backwards (letters turning around).
'to be around' indicates putting letters inside.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'hope' written backwards gives 'epoh'.
'epoh' going around 'c' is 'EPOCH'.
'for' acts as a link.
(Other definitions for epoch that I've seen before include "extended period" , "Sure date" , "Period of time marked by a great event" , "Period of notable events" , "Long period of time" .)