I know tomorrow is a holiday, so what stores will be open tomorrow and Monday as well.
The businesses that Eddy named, supermarkets, bars, etc., will be open as usual. Offices will be closed, as will many retail stores. Businesses have to pay employees extra if they work on holidays.
Tomorrow is Dia Virgen de La Altagacia. This is a Catholic day, but observed as a national holiday. Monday is Duarte Day. The actual day is the 26th,but is being celebrated on Monday to make a long weekend. Duarte is considered the founding father of the DR since he led the successful effort to gain freedom from Haiti in 1844