Dress
In malls and other public places, dress modestly: the FCDO advises women to cover shoulders and knees. Swimwear is for the beach and the pool only. Mosques set stricter rules. At Sheikh Zayed Grand Mosque women need loose, ankle-length clothes, long sleeves and a headscarf, and men should ideally cover their legs.
Ramadan
Ramadan moves about 11 days earlier each year, so check the dates for your trip. Non-Muslims don't fast, but in daylight hours you shouldn't eat, drink, smoke or chew gum in public, play loud music or dance. Some restaurants close or change their hours during the day. After sunset, the iftar meal makes for lively evenings.
Alcohol
You must be 21 to drink in Abu Dhabi, Dubai and most of the Northern Emirates, and you can drink in licensed hotels, bars and restaurants. In Sharjah drinking or possessing alcohol is illegal. Anywhere in the UAE, it's illegal to drink in public or be drunk in a public place, so plan your ride home.
Behaviour in public
Public displays of affection are frowned upon, and you can be arrested for kissing in public. Swearing and rude gestures are illegal, online too. Ask before you photograph people, and don't photograph government buildings or military sites. The UAE has zero tolerance for drugs, including cannabis.
The weekend
Since 1 January 2022 the federal government has worked a four-and-a-half-day week, with Saturday and Sunday off and a half day on Friday. Most emirates did the same. In Sharjah the official weekend is Friday to Sunday. Friday midday prayers still shape the day: at Sheikh Zayed Grand Mosque the prayer hall is closed to visitors from 12pm to 3pm.
Food and drink
Accept the coffee. Gahwa and dates are still how Emiratis welcome a guest, and in Abu Dhabi you can learn the ritual at Bait Al Gahwa, beside Qasr Al Hosn. In Dubai, the Sheikh Mohammed Centre for Cultural Understanding serves Emirati breakfasts on floor cushions in a courtyard in Al Fahidi, and its hosts are happy to take questions. Alcohol is served in licensed hotel restaurants and bars in Dubai and Abu Dhabi, but not in Sharjah. During Ramadan, the iftar meal at sunset is when restaurants come to life.