So, I’ve come back and re-read this post and I think this is actually what I’m after all along? ! (apologies! thank you)
So I guess the only improvement would be for simpler users, perhaps having buttons or sliders for days / weeks / hours and what have you. Though I think I can operate a calculator and work out what I’m trying to do.
Now my other post which was related to this, bandwidth control / throttling and possible scheduling of when backups upload (Regardless of snapshot time) might be quite useful!
However, I think with a bit more careful reading I’ve realised this should cover the job, thank you.