problem with time of day
I had a strange problem with Timex watch software for the PC back in a similar timeframe.
The software would only work between midnight and noon EST, and got a non-indicative error between noon and midnight EST.
So I used it in the morning for some time.
I eventually did determine what the error was.
My computer was running with a 24-hour clock option rather than a 12-hour clock option.
The Timex software was written assuming a 12-hour clock, so hours 13-23 were not acceptable.
I sent an email, but the bug was never fixed.
After that discovery, if I needed to update the watch after noon, I temporarily changed the system clock to 12-hour.