Hours of Operation
Banks in Buenos Aires are only open weekdays 10-3 all over the country. Government offices are usually open to the public on weekday mornings from 7 to noon or 1. Government offices, banks, and post offices close on all public holidays, but malls and supermarkets generally only close on Christmas, New Year's Day, and Labor Day (May 1).
Private businesses are generally open weekdays 9-7. Malls and clothes and souvenir shops 10-8 or 9; and supermarkets 8:30 am-9 or 10 pm. Shops that aren't part of chains or in malls are often closed Saturday afternoon and Sunday, except in Palermo Viejo, where Monday is often the day they close.
Post offices are open weekdays from 9 to 5 or 6 and Saturday 9-1. Telephone centers generally stay open daily 8-8 or later. Most gas stations are open 24 hours.
Museums usually close one day a week (Tuesday is common), and often shut their doors for a whole month in summer. Restaurants generally don't open for dinner until 8:30 or 9 pm but stay open until midnight or 1 am. Most bars don't get going until midnight, and often open right through the night. There's no official last call.