In all hotels, you can change currency at the hotel reception. As a rule, the exchange at the reception works in the morning and evening.
Only dollars and euros can be exchanged at the reception for the local currency — the Tunisian dinar. The currency exchange rate is about the same everywhere, it is regulated by law.
The inverse exchange is carried out only at the airport if there is a receipt for currency exchange. Therefore, it is better to exchange dollars for dinars in small amounts.
Exchange offices in the city work, as a rule, from 9 to 20. The schedule may change during Ramadan. Banks are open from 8:00 to 16:30.