time of day

NOUN
11 LETTERS · STARTS WITH T

time of day is a valid 11-letter word worth 18 points in Scrabble and 18 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1I1M3E1O1F4D2A1Y4
1 + 1 + 3 + 1 + 0 + 1 + 4 + 0 + 2 + 1 + 4 =18 PTS
DOUBLE WORD → 36TRIPLE WORD → 54
MEANING

What does time of day mean?