Levelling out late in the day (7)
I believe this clue is a double definition.
'levelling out' is the first definition.
(making even or level)
'late in the day' is the second definition.
(time of day)
(Other definitions for evening that I've seen before include "Some Enchanted - - (song)", "The close of a day; a word used in the first ever 2 dn", "When day becomes night", "after dark?", "Pressing - time of day".)