I had a Mido All Dial Chronometer serviced by a trusted watchmaker and worn it since for about two weeks.
Within that time, it ran about - 3 seconds per day, which I find very respectable.
I took the watch with me oversea, set the time again on the plane 2 days ago, and it's been running +25.5 seconds per day! (today it hit +
I'm not sure what happened. Personally I'm ok with +25.5 per day, but how did my watch went from -3 to +25.5 in such a short period of time?
The watch is not magnetised or exposed to any common killers. It's not knocked or anything close to that (I worn it on my wrist on the flight).
Could it be temperature? The watch was serviced in a tropical country with temperature around 30C, and now I'm back to a dried and cold environment with the temperature at around 15C.
Other than that, I'm not sure what else...