As it is in any Islamic country, the call to prayer is called out from mosques five times a day starting in the early morning. It can be a beautiful sound. The people of Aleppo were possibly the most friendly people that I have met in my travels. Regular folk on the street will offer you a chair if you seem tired and then offer you some water or tea. Aleppo is a fairly conservative city. Dress appropriately to avoid any problems and to avoid standing out too much. Men should wear regular shirts and long pants and women should not wear anything that is too revealing. If you follow that simple dress code you should not have any problems. Headscarves are not necessary unless you want to enter a mosque but even then grey cover-all robes are available at no extra charge.There were no hostile feelings towards Americans however you could find yourself in trouble if you speak against the Syrian government too much. Your best bet is to avoid political conversations all together just to avoid any possible problems.Friday is a holy day and most shops and historic sites are closed so plan accordingly for this.Stealing is looked down upon and thus is not very common. Crime is generally low and you should feel safe to walk around in any part of the city at any time day or night. But as in any city, its a good idea to keep an eye on your belongings, particuarly in the suk.Meals are a bit later than in the U.S. but similar to the times in some European countries. Lunch is from 1 to 3 and dinner around 8pm. Syrians take a siesta in the middle of the day, from about 3 to 6, but this means that the night life is very active. You can return to the markets and public squares that you visited during the day and by 10pm they will be bustling with people selling food and treats and drinks. It is a like a street fair every night.Aleppo is a beautiful and historic city that anyone who is considering a trip to the Middle East should go see. http://wikitravel.org/en/Aleppo