Lunar Year
lunar year consists of 355 days which are divided in twelve months each having either 29 or 30 days
it has 10 days less than the solar year which comprises of 365 days and is based on one complete revolution
of earth around the sun
georgian calender follows the solar year and all the events in the christian world occur according to the georgian calender
this is why christmass will always come in december which will fall in winters
on the contrary the islamic hijri calender follows the lunar year and all the events of islam occur according to the islamic calender
this is why if the holy month of ramazan falls in some areas in summer and in some other areas in winter
this will not remain the same always as the climate in which ramazan will come will keep on changing and after exactly 18 years the climate will be exactly opposite i.e places who had ramazan in summer and people their had to fast in extreme hot conditions
will now have relaxation of fasting in winters and vice versa
such is the justice of our Almighty God the most beneficient and ever merciful