Hi,
I have a start date and time in C1 e.g 01/07/2017 16:25:00 (date is in DD.mm.yyyy format ). In D1 I have an end date and time e.g 01/07/2017 22:15:00. The day is not relevant and is always the same in both cells.
I then have the day broken down into half hour chunks eg A2 has 00:00 and B2...