So is it Veterans Day, Veterans' Day or Veteran's Day?

And is it Presidents Day, Presidents' Day or President's Day?

And is it Mothers Day, Mothers' Day or Mother's Day?

(And if somebody tells me that is a YART, I don't care, because about 4000 of the people who used to be here aren't here anymore and the remaining 50 who were here when this may have been discussed before can afford to be gracious, for the benefit of the newcomers.)