Splitting data based on daynumber and get the belonging rows

I have a dataset with datenum values in one column and another column with numbers(counts). The datenum values are the date + time. I need to calculate certain values per day and afterwards per specific timeframe in a day. I have been able to split this data by day using the following code:

TimeData = (:,1);
CountsData = (:,2);
TimeDataDay = datevec(TimeData);
TimeDataDay = TimeDataDay (:,1:3); %only return the date
UniqueDate = unique(TimeDataDay);
DataDay = [TimeDataDay, CountsData] %returns only date vs counts

DataDay1 = UniqueDate(1,:) 
[row,~] = find(DataDay == DateDay1)
DataD1 = DataDay(row,:);

So now DataD1 is the date vs the counts. It does not display the time. However, I need to get the date + time vs the time. Is there a way to do this?

[KSSV]

datevec should give you time also....

[Debbie Oomen]

yes it does with the original data, but that is why I only used to 1:3 columns. To only get the date and ignore the times. The dates are unique but the time is not so therefor I only used these columns. To split the data into days

[Guillaume]

Which version of matlab are you using? Any reason you're not using modern tools such as timetable, and possibly discretize, splitapply, etc.?