How to adapt a cheap digital stopwatch / clock to record fridge run time

[Dust bunny]

My boat refrigerator runs on 12 volts DC. I'd like to adapt a 'cheap' digital clock or stopwatch to time how long the fridge runs for. I wired in a counter that counts how often the compressor starts, but that doesn't really help as I need to know how long it runs each time it comes on and total run time in say, 24 hours.
I was thinking a digital stopwatch utilizing the lap time counter, but what do you think; is this possible?
Thanks in advance for your time!

 

[CocaCola]

Quick and dirty get an analog clock of the proper voltage and wire it parallel to the compressor... Set it for 12:00 and see how much time elapses in a day... You won't get individual run periods but I don't see how that is really all that important if you can average the 24 hour period out... Also ambient temps and the amount of items in the fridge can have a drastic effect on run time... Logging the individual run time is a little more involved, I would do it with a micro but that kinda involved for a newbie...