I have got your idea and write a code for you:
startdate = datetime('2020-01-02');
enddate = datetime('2020-05-15');
dt = enddate - startdate;
dday = hours(dt)/24 + 1;
TT = timetable('StartTime',startdate,...
'TimeStep',caldays(1), 'size',[dday,3],... % 1 day as time step
'VariableTypes',{'double','double','double'},...
'VariableNames', {'Ones', 'Twos', 'Threes'});
TT.Ones(:) = 1;
TT.Twos(:) = 2;
TT.Threes(:) = 3;
You can see timetable is enough to create such a table but a little bit complex.
TT =
135×3 timetable
Time Ones Twos Threes
__________ ____ ____ ______
2020-01-02 1 2 3
2020-01-03 1 2 3
2020-01-04 1 2 3
2020-01-05 1 2 3
2020-01-06 1 2 3
2020-01-07 1 2 3
...
2020-05-11 1 2 3
2020-05-12 1 2 3
2020-05-13 1 2 3
2020-05-14 1 2 3
2020-05-15 1 2 3
