The unusual day of February 29 comes up on the calendar only every four years. In American English, February 29 is called a leap day. And the entire 12-month period with a February 29 in it is called a leap year. The year 2020 is such a year.

As a verb, the word "leap" means to jump, or to move quickly. "Leap" can also be a noun, meaning a jump or a sudden move. In a leap year, the dates jump over one day of the week. In 2017, the last day of the year December 31, fell on a Sunday. In 2018, it fell on a Monday. In 2019, it fell on the Tuesday. But in 2020, December 31 will fall on a Thursday. It just leaps right over Wednesday. "Leap" is also an important word for two American expressions. One is a kind of warning. If you want someone to investigate （调查） a situation completely before taking action, you might say "look before you leap". The other expression is a phrase of hope. Advising someone to "take a leap of faith" invites the person to take action, even if not everything about a situation is known.

Interestingly, both phrases are completely reasonable to say to someone who is about to get married.

On that note, some people choose to marry on February 29 because it is an unusual day. But some ancient people would likely tell couples not to do it. Leap years were believed to be difficult, and leap days were unlucky and a bad time to begin anything new.

Whatever you think about them, the changes in the calendar will be gone soon enough. Then we can return to normal, and leap over February 29 as usual.