Attach a shade on the side of the light which directly effects your neighbor. Large plant/statue/tree to reduce/eliminate problem. You can also add another schedule as others suggested to turn off after it’s been on for a specified amount of minutes. Still I would rather see if I can block the light to my neighbor so that I can use my smart light whenever and however I want :)

Giving access for your smart switch to your neighbor is no-no for me.