Database structure for grouping on day

Hi there,

I ak building a schedule module. Currently I hava simple list of activities with a start date/time and end date/time.

I want to render these in a repeating group, but grouped by day. From a performance perspective what is the best way to setup this datatype

Should I split date (day) and time for both start and end or can I group data in the RG based on start date/time?

Or should I add a separate datatype (Dates). Then the activity datatype only has start time and end time fields with a link the to the datatype:Dates for both start and end date?

The grid would be based than on an RG dates and in each cell an RG of activities.

Looking forward to see some insights on this.