I have been remiss in not noting the start of Ramadan. Ramadan is the ninth month of the Islamic calendar and devout Muslims fast during the daylight hours throughout the month. This means that they may not eat, drink, smoke, or have intercourse while it is light outside. Traditionally, it is light when one can distinguish between a light thread and a dark thread. Ramadan started August 1 in our Gregorian calendar and will end on August 29 this year.
The Islamic calendar is a lunar calendar. Unlike the solar Gregorian calendar, The Islamic calendar is based on the phases of the Moon. There are twelve months of 29 or 30 days with extra days added in a thirty year cycle to keep the calendar in phase with the Moon. The problem is that twelve Moons add up to 354 days, eleven days shorter than the solar year. Most cultures with lunar calendars add a leap or intercalary month every few years, the exact cycle depending on the calendar. Moslems, however do not add an intercalary month. There is even a verse in the Koran that forbids adding an extra month.
The number of months in the sight of Allah is twelve (in a year)- so ordained by Him the day He created the heavens and the earth; of them four are sacred: that is the straight usage. So wrong not yourselves therein, and fight the Pagans all together as they fight you all together. But know that Allah is with those who restrain themselves
Verily the transposing (of a prohibited month) is an addition to Unbelief: the Unbelievers are led to wrong thereby: for they make it lawful one year, and forbidden another year, in order to adjust the number of months forbidden by Allah and make such forbidden ones lawful. The evil of their course seems pleasing to them. But Allah guideth not those who reject Faith. Koran 9:36-37
For this reason the Islamic calendar is not synchronized with the seasons. The year cycles through the season every 33 years. It is as if Christmas were in winter one year, autumn six years later, summer even later, and so on. Because the Islamic calendar is not synchronized with the seasons it cannot be used for agricultural purposes. A farmer couldn’t plant, harvest, etc on the same date or month as the previous year because they would not correspond to the proper seasons. Nowadays, outside of Saudi Arabia, the Islamic calendar is used only religious purposes. For other purposes, the Gregorian calendar is used.
The calendar seems impractical compared to the Gregorian calendar but it does have one advantage, in that the fast of Ramadan cycles through the seasons so that for at least part of the 33 year cycle, the fast is held in the cooler, winter season with shorter days. But, then, for part of the cycle, including this year, the fast is in the summer with the longest days of the year.