Stop working for 24 hours after phone conversation on IT (4,2,1,3)
I believe the answer is:
call it a day
'stop working' is the definition.
'24 hours after phone conversation on it' is the wordplay.
'24 hours' becomes 'aday'.
'after' means one lot of letters go next to another.
'phone conversation' becomes 'call'.
'on' means one lot of letters go next to another.
'call'+'it'='callit'
'aday' put after 'callit' is 'CALL IT A DAY'.
'for' is the link.
(Other definitions for call it a day that I've seen before include "Set the style for a 24-hour period" , "pack up" , "Abandon work for now" , "Decide to stop doing something" , "sign off" .)