WASHINGTON – Because of a quirk in the calendar, US President Barack Obama will recite his official oath of office for a second term Sunday, out of public view, before repeating the act for hundreds of thousands of spectators on Monday.The US Constitution requires that the inauguration take place on January 20, but because that date falls on a Sunday this year, when federal offices are closed, there is only a private event that day with the tradition public version conducted the next day.Accordingly, on Sunday morning, Obama and Vice President Joe Biden are participating in official swearings-in at their homes, the White House and the Naval Observatory, respectively. The swearings-in is proceeded by an official wreath-laying ceremony at Arlington National Cemetery in nearby Virginia. Later Sunday, there will be an inaugural reception where both men will deliver remarks.On Monday, Supreme Court Chief Justice John Roberts will re-administer the oaths on the steps of the Capitol before assembled dignitaries, the press and a crowd expected to number close to one million spectators, far fewer than attended in 2008. Obama will then deliver his second inaugural address.The event will be proceeded by a church service attended by the first and second families, and followed by a public parade. In the evening, the Obamas will make appearances at just two inaugural balls, a sharply scaled back number in contrast to previous years.Already on Saturday, however, the inaugural festivities had kicked off with a day of service.The Obamas participated themselves by visiting a local Washington school in the morning to help make it over.This year’s inauguration coincides with Martin Luther King Day, and the day of service is seen as a way to promote King’s legacy. Obama began the tradition with a hope that it would become an inaugural tradition.To broader the day’s scope, former first daughter Chelsea Clinton is chairing a volunteer summit on the National Mall Saturday that also includes performances by famous musicians and actors, and volunteer events have been organized by the inaugural committee throughout the country.Jewish groups Repair the World and the Washington DC Jewish Community Center are among the 100 participating organizations.Jewish groups will also be getting in on the inaugural action on Monday. J Street, for one, plans to have volunteers stationed throughout the Mall to recruit supporters to join their campaign to lobby the White House and Congress for work toward a two-state solution.