When is leap year

A leap year is a year with one additional day or even additional month in lunisolar calendars. A calendar that is containing the same number of days as every year has must drift in accordance with the event. Occasionally, a day or a month is inserted in it so that its drift may be corrected. Except leap year all years are referred as common years. A common year has 365 days in it. A leap year may contain 366 days or 13 months according to different calendars.

Solar Calendar:

A very common solar calendar is Gregorian calendar. If we talk about leap year, in February there are 29 days where in common year February has only 28 days. According to this calculation the days in a leap year become 366 instead of 365. On the other hand if we talk about the Hebrew calendar, an additional month is added in it when leap year is there. So that leap year is of 13 months instead of 12 months. It is added to the 12^th lunar month at every 19 years. Those years which are not divisible by 100 evenly not refer to as leap years. It is said as leap year when it is evenly divisible by 400. We can take an example of 1600; it is totally divisible at 400, so it is a leap year where 1700 is not a leap year. Calculation of leap year is very easy. Now we can easily say that two millennia duration contain four hundred and eighty five leap years. If we calculate the days according to this rule we may say that a year contains three hundred and sixty five days plus five hours forty five minutes and twelve seconds. Now if we come up to view the Islamic calendar either observed or calculated, it does not have regular leap years. Both observed and calculated have 12 months containing 29 or 30 days. In Islamic calendar the leap years were prohibited in 632 CE.  Since Allah created the beautiful earth and the heaven above, it was ordered that there are only 12 months in an Islamic year. Among them, four are the sacred months of the year. That was the straight practice.

Conclusion:

From the above conversation, it can be easily concluded that a leap year varies as we go through different calendars like Gregorian calendar, Hebrew calendar and Islamic calendar as well.

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