Weekends is simple:
TT = TT(~isweekend(TT.Time),:)
Holidays are another story, but if you have a list of the ones you care about, use ismember on TT.Time. You may need to use dateshift to "round" to whole days, depending on what your data look like. Perhaps something like
Also, if you have access to the Financial Toolbox, you can use that to generate a list of dates to remove.