Ramadan is the ninth month in the Islamic calendar. It is the month when every healthy man and woman should fast from dawn until sunset for a whole Lunar month. An Islamic month always begins at night on a new Moon. That is when the Moon is invisible in the night sky, the dark side of the Moon.
Ramadan is the month in which the Quran was revealed and chapter two, The Heifer, verses 183 – 187, tell us everything we need to know about the rules of fasting. The verses say that fasting is decreed so that salvation may be reached. It says that if you are sick or traveling you may substitute those days with others. It tells us that sexual intercourse is not permitted during the fasting hours but is permitted during the night. We are told that we may eat and drink until the white thread becomes distinguishable from the dark thread at dawn.
God refers to husbands and wives as the keepers of secrets and tells people who stay in the mosque for the last ten days of Ramadan that sexual intercourse is not allowed at all. God also says in these verses that He is always near us and that He answers our prayers when we pray.
Chapter 2, verse 186
When My servants ask you about Me, I am always near. I answer their prayers when they pray to Me. The people shall respond to Me and believe in Me, in order to be guided.
There is no need to wait for the sighting of the crescent Moon because for centuries before the Quran came to mankind they knew that a new Moon began a new Lunar month, and God says,
Chapter 2, verse 189
They ask you concerning the new Moons! Say, "They provide a timing device for the people, and determine the time of pilgrimage. It is not righteous to beat around the bush; righteousness is attained by upholding the commandments and by being straightforward. You shall observe God that you may succeed.”
There are no other rules concerning Ramadan, just no eating, no drinking and no sexual intercourse from dawn until sunset. If you are ill you do not have to fast but can make up the days at some other time when you do not feel ill. Likewise, if you are traveling, make up the days or if for some other reason you cannot fast that day, feed someone less fortunate. God wants convenience for us not hardship.
Fasting is not easy in some countries when the days are very long and hot. But there is no substitution for fasting, it is by far the best thing for us during the month of Ramadan.