PORTSMOUTH — Have you ever wondered how other calendars deal with the extra day associated with a leap year? Here's a quick guide to help you sort it all out. The Gregorian calendar The Gregorian ...

Every June, Birches Elementary School mathematics teacher Judy Rose challenges some of the school’s first, second and third grade students with a “Math Calendar” that they can complete over their ...

When I read that this July was extremely rare (823 years), it didn't seem right, so I got to thinking about calendars. The first of January has to start on one of the seven days of the week. So for ...