Waiting for that to be resolved before the day is out (2,3,5)
I believe the answer is:
at the ready
'waiting' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'that to be resolved before the day is out' is the wordplay.
I cannot quite see how this works, but
an anagram of 'that' is 'atth' which is within the answer.
'before' could be 'ere' (poetic term) and 'ere' is located in the answer.
an anagram of 'day' is 'ady' which is within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for at the ready that I've seen before include "Prepared or available for immediate use" , "Poised for action" , "Available for use in operating" , "on standby" , "dipping hand in till?" .)