To make it short – here are the facts first:
Denmark has from 30.06. until 08/11 Summer holidays.
Sweden has from 11.06. until 08/19 Summer holidays.
It’s the same about every year. During this period the holiday homes in Scandinavia, we are interested in Denmark, are particularly expensive. Before and after that, the price drops by almost half.
In recent years, for example, the residents of Mecklenburg-Western Pomerania with school-age children have been very lucky because the summer holidays lasted until the beginning of September. So it was possible for almost 3 weeks to go on holiday very cheaply. This year, however, the summer vacation ends on August 18th. in MeckPom, so that now you can only get a cheap holiday in Denmark for one week.
So if you don’t have children who have to go to school, you should book outside of the Danish holiday periods described.
If you have school-age children, you have to calculate and see where you can save and you have to orientate yourself from mid-August.
If you are not that price sensitive, you can book when you want and it is best to do so directly during the Danish summer holidays, because then the range of concerts and castle festivals is greatest.