A year from today, the US will inaugurate a new president. But inauguration day has not always been thus fixed.
In the early years of the Republic, habit (rather than statute) placed the date of inauguration at March 4—though even that convention was not quite firm. In 1821, with the incumbent President James Monroe about to take the oath of office for his second term, March 4 fell on a Sunday. Monroe asked of Chief Justice John Marshall whether he could take the oath on the following day, rather than sully the Lord’s day with secular business.