Monitor up-time of Osram plugs

Dear community,

I use Osram Plugs quite extensively. One is connected to a humidifier which needs changed every 40 days (i.e. 40x8=320hrs) or so.
Now, is it possible to visualize the time it has been running in on-state and by that have some sort of notification when it is time to change the humidifier?
Alternatively, I could simply use a manual timer that counts down 320hrs. I would, however, prefer a semi-automated version of this.

Any and each idea is welcomed!