Even if you're brave (read: suicidal) enough to visit Afghanistan these days, you should still avoid large gatherings, particularly those marking national and Muslim holidays. But, should curiosity get the best of you, cover yourself according to the strictest local custom and check out these celebrations.
One of the most important holidays in Afghanistan is Navrus (New Days), celebrated around March 21, on the spring equinox. It's an Islamic adaptation of far more ancient festivities, and special foods - wheat for the ladies and veal for the men - are prepared. Wine is traditionally part of the service, but that custom has been put on hold by the puritanical Taliban. Navrus is a family affair these days, though some communities still take it into the streets.
Liberation Day takes place on April 18, and probably isn't the party to flaunt any connections you might have with the West. It's followed by Revolution Day, April 27, making the whole month a great time for flag waving. May 1 means Labor Day, here as in all the former Soviet republics. Independence Day is celebrated August 18 with at least some fanfare.
The four major Islamic holidays are celebrated according to the lunar calendar, so check the dates and plan ahead. Eid-ul-Azha, the Feast of Sacrifice, marks the beginning of the hajj, or pilgrimage to Mecca. Those who can afford it buy and slaughter an animal, then share the meat with friends and strangers. Mawlid-an-Nabi, the Prophet Mohammed's birthday, is much more low-key.
Ramadan is the month of fasting. From sunrise to sunset devout Muslims who can physically handle it are asked to go without food, drink, cigarettes and just about everything else. It's illegal - not to mention very, very rude - to do any of these things in front of people observing this important holiday. Eid-ul-Fitr marks the end of Ramadan, when friends and families gather to eat, eat and, if so inclined, smoke cigarettes.