I do not keep track of any kind but i use this method. I have 14 razors that i use as a 7 day sets. Other set waits honed in a drawer. As the first razor of the set currently in use shows any signs of needing a touch up, i just put it aside and get on with the last 6. Keep on shaving until the last razor gets aside. Then i take my second 7 day set in use. Usually one set lasts about 6 months or even more so there's plenty of time to hone the other set before it gets back to service again.