Hi all. :)
I was trying to measure a P2 over 24 hours. I used my phone at first, then a modern Casio watch's stop watch, then another modern Casio watch's stop watch, and a 15 year old Seiko watch's stop watch. I noticed that if I started them all at the same time, after 24 hours, everyone had drifted slightly in a different way.
Is there any other method I can try (without buying any new kit)? Maybe an online clock, or something similar?
Thanks.