Twenty four hours on island for personal assistant (3,6)
I believe the answer is:
man friday
'personal assistant' is the definition.
'man friday' can be an answer for 'assistant' (man Friday is a kind of assistant). I am unsure of the 'personal' bit.
'twenty four hours on island' is the wordplay.
'twenty four hours' becomes 'friday' (I can't justify this - if you can you should give a lot more credence to this answer).
'on' is a charade indicator (letters next to each other).
'island' becomes 'Man' (the Isle of Man is an example).
'friday' put after 'man' is 'MAN FRIDAY'.
'for' is the link.
Can you help me to learn more?
(Other definitions for man friday that I've seen before include "Title or name of Robinson Crusoe's servant" , "loyal helper ..." , "Faithful servant" , "Male factotum" , "Male helper" .)