Regardless of whether it's 30 minutes, or 60, or 65, I recently hit the roof when I was told something similar by another ISP. I despair that the ISP support people don't seem to understand many people have a home network that is not JUST used for internet access, and the router often plays an important role as an ethernet switch, DHCP server etc.
If I were to 'turn my router off for 65 minutes' certain devices would lose access during that time to much of my NAS storage, bringing certain work and pastimes to a grinding halt. Some parts of the house, fed from the router's switch, would also lose access to media & TV recordings as well as my preferred method of access for live TV.
If they mean 'disable your internet connection' I wish they'd say so. Yes, I can translate it for them, but I then end up being forced to 'lie' to the support staff when I tell them I've complied with their request.
Another one I hate is when I'm told to 'switch off my computer for some time', which often seems appear early on the script whenever the internet connection goes down. My response is 'which one?'.