This year, the observance of the birthday of Martin Luther King, Jr., will be celebrated on Monday, Jan. 21. According to the Office of Personnel Management, by federal law, it is a public holiday for federal employees, with the exception of those in the District of Columbia, Montgomery and Prince George's counties in Maryland, and Arlington and Fairfax counties and Arlington City in Virginia, where the Martin Luther King, Jr., holiday is celebrated concurrently with Inauguration Day.

As such, in Montgomery County, PA, post offices will be closed, there will be no residential mail delivery, and state, federal and many municipal government offices will be closed. Most banks will also be closed.

Here is a list of other things that might be open or closed on Jan. 21, in observance of the holiday:

Libraries:
Upper Dublin Public Library - open
Wissahickon Valley Public Library - open
Abington Township Public Library - open
Lansdale Public Library - closed
Royersford Public Library - open
Montgomrery County - Norristown Public Library - open
Perkiomen Valley Library - open
Pottstown Regional Public Library - closed

Schools:
Upper Dublin School District - schools closed/Day of Service
Wissahickon School District - schools closed/Day of Service
Abington School District - schools and offices closed
North Penn School District - schools closed
Spring-Ford Area School District - schools closed
Norristown Area School District - schools closed
Pottstown School District - schools closed
Pottsgrove School District - schools closed
Methacton School District - schools closed
Perkiomen Valley School District - schools and offices closed
Colonial School District - schools and offices closed
Philadelphia area Catholic schools - schools closed

Area malls:
Montgomery Mall - open
Plymouth Meeting Mall - open
Willow Grove Park Mall - open
Coventry Mall - open
King of Prussia Mall - open
Philadelphia Premium Outlets - open

Other:
PennDOT Service Centers - closed Jan. 19 and 21
SEPTA public transportation will operate on a normal Monday schedule
Montgomery County Courthouse - closed