The standard deviation is expressed in the same units as the mean is, whereas the variance is expressed in squared units, but for looking at a distribution, you can use either just so long as you are clear about what you are using.
2322. Presidents Day (or Presidents' Day), is the common name for the federal holiday officially designated as Washington's Birthday. As the first federal holiday to honor an American citizen, the holiday was celebrated on Washington's actual birthday in 1796 (the last full year of his presidency) on February 22.
The eve of the Inauguration Day, January 19, 2009, fell on Martin Luther King, Jr. Day, a U.S. federal holiday in recognition of Dr. King 's birthday. Obama called upon communities everywhere to observe the King Day of Service, a day of citizen volunteer service honoring the human rights leader.