Monday has arrived with both Inauguration Day and Martin Luther King Day in the U.S., but it is known elsewhere as Blue Monday.
Weeks after Christmas décor is taken down at the New Year has set in, so-called Blue Monday supposedly leaves people feeling down.
The day is believed to have been part of Sky Travel magazine's publicity campaign, but it is referred to as the most depressing day of the year.
Dr. Cliff Arnall, a psychologist at Cardiff University, reportedly devised an equation for the campaign that calculates debt, motivation, weather, and need to take action and founded Blue Monday, according to the U.K.'s The Guardian.
However, Yahoo notes that Arnall's scientific claim has come under fire over the years. The psychologist recently responded to the criticism.
"I'm pleased about the impact it if it means people are talking about the depression and how they feel but I'm also encouraging people to refute the whole notion of there being a most depressing day and to use the day as a springboard for the things that really matter in your life," according to The Telegraph.
Meanwhile, late June, or midsummer, has been referred to as the happiest day of the year, according to the U.K.'s Daily Express.
"The third Friday in June came out with the highest rating due to peaking happiness factors such as warm summer evenings outdoors, seeing friends more frequently, and excitement about holidays," Dr. Arnall told the Daily Express.
Alternately, Jan. 21 is certainly a busy day in the United States this year as Barack Obama is publically sworn in as President for the second time. In a rare occurrence, Inauguration Day coincides with the annual day of remembrance of the civil rights leader Dr. Martin Luther King Jr.
Meanwhile, Inauguration Day is marked by the President making an oath or affirmation before that person can "enter on the Execution" of the office of presidency, as mandated by the United States Constitution.
President Obama made a private oath of office on Sunday, with the public swearing-in on Monday morning before hundreds of thousands visitors watching in the nation's capital.