no
To find out how many schools were closed a previous week, you could look in that week's newspapers for schools that were closed in your area.
Schools were not closed during World War 1.
No they are not closed.
Closed
If New York City schools are closed, they would be closed on the third Monday of February for Presidents' Day.
Any kind of schools can be closed permanently or temporarily due to emergencies or weather.
Schools are not closed for Lincoln's birthday, though many are closed for President's Day.
Schools are not usually closed on Halloween.
Oklahoma City Public Schools are closed only because the subject is plural and must have a singular verb "are."
To find out how many schools have been closed in 2013-2014, you would need to check newspapers or call schools to find out if they have beeb closed.
Veterans Day is a national holiday and most banks are closed. Schools may or may not be closed.
If you want to know how many schools were closed on a day that has been a while back, yoi could look in the local papers of that time to find out the schools that were closed in your area. If you want to know what schools were closed in another area,. you would need to look in newspapers from the area the schools are in.