Machine-readable representation of a sensor duty cycle / recording schedule

My group is currently trying to improve the database we use to store our recordings, and we're trying to figure out how to represent a sensor's duty cycle in a way that is consistent and machine-interpretable. Obviously for a very simple duty cycle you could do something like 10on20off, but things can start to get a bit more complicated if you wanted to, for example, run sunrise to sunset, or run every other day, or increase your recording effort around dawn and dusk choruses, or even some combination of all of those things. Ideally, the duty cycle representation could be a relatively short text string.

Is this something that anybody here has tried to put together? Any thoughts on the topic?