Opening hours vary throughout the year, especially for sights and activities.
Banks 10am–4pm Monday to Friday
Bars & Clubs 4pm–midnight, to 2am or later Friday and Saturday (on weekends clubs may open until 5am)
Cafes 8am–5pm or midnight
Restaurants noon–10pm (maybe earlier on weekends for brunch)
Shops 10am–6pm Monday to Friday, to 4pm Saturday, some larger stores may open Sunday
Supermarkets 8am–9pm (many with in-store bakeries opening around 7am)
Family-friendly attractions (museums, zoos, funparks) in holiday hotspots will generally open from June to August (possibly May to September), and for the spring and autumn school holidays.
The Danish summer vacation, which generally runs from the final week of June through the first week of August, is a six-week period when opening hours of attractions are longest. Hours generally decrease in the shoulder and low seasons.
Websites are the best place to find comprehensive, current information on opening times.