Ramadan was a non-Muslim pagan Arab festival  The difference
between pre-Islamic Ramadan and Islamic Ramadan is, pre-Islamic
Ramadan was practiced by a Pagan tribe in Arabia, and Islamic
Ramadan is practiced by Muslims all over the world.  During
Ramadan, Pagan Arabs used to abstain from food, water, sexual
contact etc. Muslims practice the same Pagan Ramadan rituals.
It is a well-known fact that Islam adapted the Pagan practice of
fasting. There is a Hadith in Sahih Bukhari that mentions the
ritual. Bukhari 5:58:172 – Narrated Aisha: ‘Ashura was a day on
which the tribe of Quraish used to fast in the pre-lslamic
period of ignorance. The Prophet also used to fast on this day.
So when he migrated to Medina, he fasted on it and ordered (the
Muslims) to fast on it. When the fasting of Ramadan was
enjoined, it became optional for the people to fast or not to
fast on the day of Ashura.’  The fasting for Ashura (10th of
Muharram) originated from a Quraish Pagan practice. Ramadan
fasting came later from Sabian trad