MATLAB: Find groups in datetime vector by date

Question

I am trying to find groups by date (dd/MM/yyyy) in a datetime vector (dd/MM/yyyy HH:mm:ss).

Herefor i tried changing the datetime format to dd/MM/yyyy and then use the findgroups function. But then each element in the datetime vector is identified as a single group. Next i tried to use g = findgroups(day(Datetimevector)). But then it is grouped by day of the month which is not the desired outcome.

How can i find groups by date in my datetime vector?

Answer 1

Datetimevector=datetime([2020 2020 2020],[02 02 10],[3 3 4],[10 11 12],[0 0 0],[0 0 0]);
rounded_to_day=datetime(year(Datetimevector),month(Datetimevector),day(Datetimevector));
g = findgroups(rounded_to_day);

Or use the older representation datenum:

rounded_to_day=floor(datenum(Datetimevector));
g = findgroups(rounded_to_day);