Excerpted from Three Years in Constantinople, or Domestic Manners of the Turks in 1844, by a Christian traveller in the Ottoman Empire named Charles White. Besides some bias as to the origin of Ramazan, his conclusion is interesting.

Ramazan - This fast, during which it is strictly forbidden to swallow any kind of food or liquid, to smoke, take snuff, or smell essences, from sunrise to sunset, commences with the certified appearance of the moon or month called Ramazan, and consequently at sunset on the last day of the preceding month Shaban. A gun is fired from each of the principal batteries upon the Bosphorus, at dawn and sunset, to warn the population of the exact time for commencing and terminating their daily fast. Ramazan ought always to contain thirty days, according to the almanack ; but the fast in the capital is sometimes reduced to twenty-nine days, when the new moon of Shawal is visible at that period. Ramazan may be compared to, and as an imitation of the Christian Lent, with this difference, that the rigid privations of the day are compensated for by the admitted relaxations of the night. This month was selected by Mohammed (Sallalahu’alaiheewassalam) for fasting, because he declared that his mission was announced to him by the Almighty upon the 19th, and the first chapter of the Kooran on the following day. Among various infractions that invalidate the daily fast, and require compensation by extra prayer and mortification, is slander. This moral fasting might be introduced with great benefit to society in Christian countries.