At the end of the day it's equally balanced (4)
I believe the answer is:
even
'equally balanced' is the definition.
(I've seen this before)
'at the end of the day' is the wordplay.
'at the end of' suggests the final letters.
'day' becomes 'ven' (I am not sure about this - if you are sure you should believe this answer much more).
The final letter of 'the' is 'e'.
'e'+'ven'='EVEN'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for even that I've seen before include "Peaceful" , "That's not odd" , "night" , "without a rise?" , "Nearly" .)