I need a "Count Up" timer

I'm about to start a series of test to different strains, I want to know exactly the time it takes from transition to harvest day on each one so I can have a better criteria when picking. I've beeen looking all over the web for a "count up" timer but all I could find is "my wedding day" countdown timer which is not getting into my garden. I wanna count Weeks and days, hours would be neat too but I'm asking too much already. So if you happen to know any appliance that do this, please help me out

It'd also help a lot remembering at which week is every system lol

Peace

Weeks and days???

How about a calendar? One with the big squares on each date for writing in time(s), notes whatever.

Or, do a search for a *Time elapsed* timer, sorta like a super long running stopwatch. They exist, but probably spendy.

Wet