01/09/2017 09:30
01/09/2017 19:30
02/09/2017 05:30 01/09/2017 2
02/09/2017 15:30 02/09/2017 2
03/09/2017 01:30 03/09/2017 3
03/09/2017 11:30 04/09/2017 2
03/09/2017 21:30 05/09/2017 3
04/09/2017 07:30 06/09/2017 2
04/09/2017 17:30 07/09/2017 2
05/09/2017 03:30 08/09/2017 3
05/09/2017 13:30 09/09/2017 2
05/09/2017 23:30 10/09/2017 1
06/09/2017 09:30 11/09/2017
06/09/2017 19:30
07/09/2017 05:30
07/09/2017 15:30
08/09/2017 01:30 easy to count how many each 24 hour period
08/09/2017 11:30
08/09/2017 21:30 then lookup each date against the new table
09/09/2017 07:30 and if 3 or more apply conditional formatting
09/09/2017 17:30
10/09/2017 03:30
in A1 it would be
=VLOOKUP(A1,mytable,2)>2