Leap day is an extra day added to the calendar every four years.

Independence Day is a national holiday in the United States celebrated on July 4th.

Save money for a rainy day.

I dream of visiting Shangrila one day.

I work a five-day week.

I always celebrate New Year's Day with my family.

I go for a run every single day.

Vernal Equinox Day is a national holiday in Japan.

I need to take a day off from work.

I worked all day long.