Solar calendar

In a solar calendar, the year begins at approximately the same place in the cycle of seasons. To ensure this, the number of days in the year must vary from year to year. This can be done by having common years of 365 days and leap years of 366 days.

The following are solar calendars

• Gregorian calendar
• Julian calendar
• Coptic calendar

The following have lunar months so are lunisolar calendar

• Hebrew calendar
• Chinese calendar

The Islamic calendar is the most well known calendar that is not a solar calendar. Its year of 12 lunar months drifts slowly through the seasons. It is a lunar calendar.