DHCP Server Lease Time

My OSMC is tethering, and running a DHCP server on RPi3.

I would like to configure the lease time. It now seems like one day.

Where and how can I configure?

connmanctl

I’ve had a good look around but what I’ve found suggests that it’s not configurable.

This post (Oct 2015) says that the tethering IP address range wasn’t configurable at the time, which tends to suggest that much of its configuration was (and probably still is) hard-coded.