There are many facts a common non-Muslims, and even some Muslims don't known about Islam. Following brief introduction will satisfy your curiosity about Islam and Muslims.
Day
Islamic day starts from sunset, means on Wednesday after sunset, Thursday is started.
Month
Islamic months are lunar based i.e. according to the monthly cycles of the Moon. Month may have 29 or 30 days. New month depends upon the sighting of moon. If the moon sighted on 29th day, then next month starts, otherwise new month will start day after next, after 30th day.
Year
The Islamic calendar starts since the year when the last prophet of Islam Muhammad (Peace Be Upon Him) and his companion Muslims migrated (Hegira) from Mecca to Medina in 622 AD.
Religions close to Islam and Muslims
Quran declares Christians and Jews close or near to Muslims than other religions, and among these two, Christians to be proved more soften to Muslims than Jews.
Compulsory Charity
2.5% or 1/40th part of wealth is compulsory to be donated as charity if the benchmark is reached consistently for a year. This compulsory charity is called zakat.
Prayer (salah)
5 prayers a day in different times of the day is compulsory worship for each adult Muslim, not to be postponed unlike fasting.
Five prayers are distributed in different times of the day so that daily routines are not affected anyway.
Fajar prayer performed before the dawn, early morning, the shortest prayer than other 4 prayersZohar prayer performed in the noon, say in lunch time, so more than a day is completed to accomplish tasks and rest of the work, official and the personal.Asar prayer, before the sunset, so most of the day is completedMaghrib prayer, just after sunset, i.e. after the completion of the dayIsha prayer, at the night, may be offered just before sleeping time, before going to bed.Limit the number of wives
Islam limited the number of wives at a time, just 4. Most religion don't limit the number of wives a man may hold at a time.
Fundamental faith
Islam is a monotheistic Abrahamic religion. The fundamental faith of Islam is that there is no god but Allah and Muhammad (Peace Be Upon Him) is the last prophet/messenger. There is no partner of God i.e. He is Alone. To faith on other as co-God or partner of the God is called shirk (we will discuss shirk below).
Unforgivable sin in the judgement day
The essential belief is followers of Islam is that God can forgive any sin if He will to, but if anyone commit shirk, will never be forgiven ever on the judgment day.
shirk is the unforgivable and worst sin declared in Islam but its punishment is not supposed to be given in this world but hereafter i.e. on the judgement day only.
Interest Forbidden
Interest is forbidden whereas profit business is encouraged. The minimum devastation of interest is implied as to undergo sexual intercourse with real mother.
shirk is the most condemned sin in Islam, but interest is such a sin that God state this as declaring war with God and his prophet.
Heirship
Islam also grant right of heirship to parents of their dead child's property or whatever he/she left behind. Heirship part is double for male immediate relatives than female, i.e. Son will get double the amount than the daughter.
Posted Article in Faith/Religion