My Citizen Eco Drive watches stopped at exactly...

Question

I have two Citizen Eco Drive Watches - one is 5 years old (never lost a second), the other is 10 months old. Suddenly two days ago at exactly 9:30 they both stopped working - I wear them all the time and they get artificial light during the times I wear them - when I don't wear them, they go in their boxes (no more than a week at a time). This is very strange - can you help?