Definition
Week
A week is a unit of time equal to seven consecutive days.
What it means
The weekday names repeat in a seven-day cycle. Move forward seven days from any day and you land on the same weekday one week later.
Remember it
Seven days make one full loop through the weekday names.
Example
Three weeks after a Wednesday is another Wednesday. The elapsed time is 3 × 7 = 21 days.
Watch for
A week can cross the end of a month or year. A seven-day interval can begin on any day, although calendars may use a set weekday to label calendar weeks.
Common mix-up
A week has 7 days, not only the 5 days often used for a school week or workweek.
Exact meaning
A week is a unit of time equal to seven consecutive calendar days.