Ramadhan

The fourth pillar of Islam, which is fasting, is practiced during the month of Ramadan. Ramadan is derived from an Arabic word for intense heat and scorched ground. (in Arabic: رمضان, Ramaḍān) – – and it is the ninth month of the Islamic (Hijri) calendar, established in the year 638 CE. It is considered the most venerated, blessed and spiritually-beneficial month of the Islamic year. Prayers, fasting, charity, and self-accountability are especially stressed at this time; religious observances associated with Ramadan are kept throughout the month.

"Ramadan is the month during which the Quran was revealed, providing guidance for the people, clear teachings, and the statute book. Those of you who witness this month shall fast therein. Those who are ill or traveling may substitute the same number of other days. Allah wishes for you convenience, not hardship, that you may fulfill your obligations, and to glorify Allah for guiding you, and to express your appreciation."[2:185]
The most holy night during the Ramadan is Laylat al-Qadr (Night of Power). It has more blessing than a thousand months. See chapter 97 of the Quran.

Fasting

The most prominent event of this month is the fasting practiced by most observant Muslims. The fasting during Ramadan has been so predominant in defining the month that some have been led to believe the name of this month, Ramadan, is the name of Islamic fasting, when in reality the Arabic term for fasting is Sawm. Every day during the month of Ramadan, Muslims around the world break their fast when the fourth prayer of the day, Maghrib, is due.