Excel Day shift and night shift schedule

Lets say I have two shifts at work.

• Day shift is from 7:00 to 17:30
• Night shift is from 18:00 to 4:30

Based on this numbers I want excel to return if its "Night Shift" or "Day Shift"

This is what i have so far with the IF statement

=IF(Q2>=7,"DAY SHIFT",IF(Q2<=17.3,"DAY SHIFT",IF(Q2>=18,"NIGHT SHIFT",IF(Q2<4.3,"NIGHT SHIFT"))))

But im not getting the results I want. Any ideas to correct the formula?