Ramadan is the ninth month of Islamic Calendar with the beginning and end marked by the astronomical new moon, so it always falls on the same day of the Islamic Calendar (a lunar calendar), but the date on Gregorian Calendar (a solar calendar) varies from year to year. It is a month of fasting, prayer, and introspection, so Muslims abstain from eating, drinking, smoking and immoral behaviors from sunrise to sunset every day. They also appreciate that non-Muslim don't eat, drink or smoke in the public.
During Ramadan, the general pace of life in Egypt slows down compared to that in normal days. Shops, museums, and historical attractions officially close earlier before sunset. Almost all Muslims try to get home or restaurant in time for the iftar (meal to break the fast) with family or friends.
Some restaurants and cafés open only after sunset and may stop serving alcoholic beverages. While almost all tourist hotels will be completely operational, including their restaurants and bars serving meals and alcoholic drinks as usual, because many tourists love to explore this amazing country during this special month.
Houses, mosques and some streets are specially illuminated with Fanous Ramadan (special Ramadan lanterns), creating a magical atmosphere. Some hotels may hold "parties" at night with very friendly atmosphere and everyone is welcome, even though you are non-Muslim.