There is no minimum length of a shift. However, companies should be aware that they must comply with their compliance "Overenskomst" if they have one.
Even though all private and companies without an "Overenskomst" can offer whatever length they want, they must also remember that it is probably few people who spend time and money on transporting themselves to a shift of 1-2 hours π
Have a good day π
Best regards,
Team Chabber