Coffee Cat Studios - Event System
I can't think of a better scenario for this than a mobile game, or any game that uses time-based systems. Even if you have to cook, craft or build, this system is the one for you. You must be able to track time somehow everything, it is impossible to individually track time, so this is a collective solution!
And now, for technicalities, this is a simple system that allows you to easily add events to your project using Unity Events and C# Events technology.
Create Area events when entering, exiting or both!
Create trigger events, when the player interacts with an object.
Create global events using C# Events.
Hopefully this asset will find a way to be useful in your project! And the best part, this asset is now free, as it used to be $1.99 but Unity decided that prices below $5 would not be allowed anymore.