When Dai was bent on taking cook out for the day (6)
I believe the answer is:
friday
'when' is the definition.
(I've seen this before)
'cook out for the day' is the wordplay.
'cook' becomes 'fry' (I've seen this before).
'out' means one lot of letters goes inside another.
'for the day' becomes 'ida' (I can't justify this - if you can you should give a lot more credence to this answer).
'fry' placed around 'ida' is 'FRIDAY'.
'dai was bent on taking' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for friday that I've seen before include "Muslim Sabbath" , ""Good" day at Easter?" , "It's payday for some" , "Robinson Crusoe's manservant" , "Crusoe's companion" .)