Friday the 13th etc.) of the year. Any month that starts on a Sunday contains a Friday the 13th, and there is at least one Friday the 13th in every calendar year. There can be as many as three Friday the 13ths in a single calendar year; either in February, March and November in a common year starting on Thursday (such as 2009, 2015 or 2026) (D), or January, April and July in a leap year starting on Sunday (such as 2012) (AG). The longest period that occurs without a Friday the 13th is 14 months, either from July to September the following
Leap year the exception that the first year starts with Hijra. In the Hindu calendar, which is a lunisolar calendar, the embolismic month is called "adhika maas" (extra month). It is the month in which the sun is in the same sign of the stellar zodiac on two consecutive dark moons. "Adhika maas" occurs once every 33 to 34 months, compensating for the approximately eleven fewer days per year in twelve lunar months than the solar calendar. Thus, Hindu festivals tend to occur within a given span of the Gregorian calendar. For example: the No Moon during Diwali festival occurs between mid