Time Scheduled Dual Wan with Merlin

[AdLion]

Hi, how can I switch between two WANs at specific time interval?

I configured my Merlin router with a Cable Primary WAN (Ethernet) and a Secondary WAN via USB Android Phone.

I would like to use the phone plan during the day (better speed but capped) and Cable at night (slower but uncapped).

Where can I find a script or how do I make one?

Thank you from a very newbie