By Cherri Gregg

PHILADELPHIA (CBS) - Hotel rooms in Washington DC are getting scarce for Inauguration Day weekend in January. You may want to check your calendars for a potential scheduling conflict.

President Obama’s inauguration is scheduled for noon on January 21st, the same day tens of thousands of Philadelphians will volunteer for the Greater Philadelphia Martin Luther King Day of Service, the largest in the country.

“King Day is a day when we celebrate the legacy of a great American and Inauguration Day is a day we celebrate a President and a nation,” says Todd Bernstein of Global Citizen. He is the founder and organizer of the Greater Philadelphia King Day Service. He says while it’s likely that some elected officials will attend the Inauguration in Washington, he expects volunteers at home will move forward with their projects.

“As exciting as the second inauguration is, I’m sure the turnout for the celebration of Martin Luther King and the King Day of Service will be strong,” says Bernstein.

Bernstein says those at the headquarters site at Girard College will get the chance to see the inauguration ceremony on large flat screen TVs.

“At 12-noon when the president is sworn in, we will show that to the thousands of people who will be in attendance.”

For more info on the King Day of Service go to http://www.mlkdayofservice.org/