"Blue Monday" is a term that is often used to describe the third Monday of January, which is considered by some to be the most depressing day of the year. The concept was first introduced in 2005 by a pr company in a press release commissioned by a travel agency. While the idea of a specific day being the "most depressing" is subjective and not scientifically proven, it does draw attention to the challenges people may face during the winter months, such as post-holiday blues, cold weather, and shorter days.