Nordic, EU/EEA and Swiss students are allowed to work in Denmark under EU regulation. There is no minimum or maximum of hours that you can work.

However, if you are receiving SU (State Educational Grant) there is a limit of how much you are allowed to earn per year. Ask your student counsellor if in doubt.

Non-EU/EEA/Swiss citizens may work in Denmark for up to 20 hours a week and full-time during June, July and August. However, this requires a work permit sticker in your passport. If you did not apply for a work permit when applying for a residence permit to study in Denmark, you can apply for one at the Danish Immigration Service. 

Please note that you work more than 20 hours a week as a non-EU/EEA-student the Danish Immigration Service can revoke your residence permit or refuse to extend it.