# Filtering a table with datatime on dates

8 views (last 30 days)
Niels Hawinkel on 28 Jul 2021
Answered: Scott MacKenzie on 28 Jul 2021
I have a table(=tmp) with column 2 (=Var2) consisting of Datetimes (Year-Month-Day-HH-MI-S). There are multiple days in this column and I want to filter out 1 day (i.e. 2019-10-01). I have tried the following:
Filter = tmp(tmp.Var2==datetime(2019,10,1,:,:,:),:);
I get the following error:
Unrecognized function or variable 'datetime'.
I have also tried the following:
Filter = tmp(tmp.Var2==datetime(2019,10,1),:);
which results in an empty table.
Anybody knows what to do?

Cris LaPierre on 28 Jul 2021
Edited: Cris LaPierre on 28 Jul 2021
In the first case, you are not using correct syntax for MATLAB's datetime function (it doesn't accept colons), so MATLAB is assuming you must have your own function or variable that does, but it can't find it.
In the second case, the == is looking for an exact match (when you don't specify time, midnight is used). None of your datetimes is an exact match.
If you are not looking for an exact match, use conditional statements instead of ==.
rmvDate = tmp.Var2 >= datetime(12019,10,1,0,0,0) & tmp.Var2 < datetime(12019,10,2,0,0,0);
Filter = tmp(rmvDate,:);

Rik on 28 Jul 2021
There is probably a native way to do this, but you could also do it yourself:
ref=datetime(2019,10,1);
L=day(ref)==day(tmp.Var2) & month(ref)==month(tmp.Var2) & year(ref)==year(tmp.Var2);
Filter = tmp(L,:);

Scott MacKenzie on 28 Jul 2021
To remove rows corresponding to 2019-10-01, this should work:
d = datetime(2019,10,01);
removeLogical = isbetween(tmp.Var2, d, d+1);
tmp(removeLogical,:) = [];

R2020b

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