Today I resurrected a 31 year old digital watch.  I’ve meant to do this for quite some time.  I got it long, long ago in 1982.  I don’t think it has been worn since about 1985 or 1986 when the Swatch craze hit.  I wasn’t even sure it would work after all these years.  I’m referring to the Timex Timebar seen below, with no model number inscribed anywhere on it.

The first order of business was locating a battery for it.  The battery had long been removed, but the case is marked with “S Cell”.  Good luck figuring out what that equates to in todays terms.  Timex doesn’t event list the battery type.  I’ve looked on and off, for quite some time, and been unable to find a replacement.  I stumbled across it today on a UK watch site buried a couple of pages deep in search results.  The replacement is a SR721SW or 362.

After getting a new battery in it I was delighted to see it come to life.  The next objective was to set the date and time.  This watch has a single button or Timebar as they call it.  I held down the left side until the seconds started blinking.  Lucky first shot!  Advance to hours, set, advance to minutes, set, advance to year, huh?

Imagine my surprise when it started flashing 1/1/70.  Wow!  My immediate thought was “I hope it works past 99”.  It’s been a very long time since I’ve seen any clock have a default date older than mid 90’s.  I pushed the right side of the Timebar excitedly and was relieved when it rolled past 99 to 00 and onward to 01!  Timex thought ahead!  Onward to 13.  07, 08, 09, ruh-roh 70.  I guess Timex didn’t think that far ahead.  So how do I get the dates to roll correctly?

Internet.  Bing to be exact.  I spent a large part of my life writing code.  I also know a thing or two about dates and date manipulation due to that work.  I realized I just needed to find a calendar year that was similar to 2013 (start on the same weekday, have the same number of days, and end on the same weekday).  Yes, yes, the year would display wrong, but I’m interested in the month and date.  A quick search in Bing yielded this page which has compatible calendar years.  Thank you timeanddate.com.

I picked 1985 from the list.  That should allow the watch to keep running for another 24 years.  1985 is 28 years ago.  Playing with the year I found that each year until 2020 you can just subtract 28 years and have a compatible calendar.  Maybe more, but I stopped at 2020 (which is compatible with 1992).  Of course the floating holidays like Memorial Day may not match up, but the days and numbers will.

With the year set, I moved to the month, day, then weekday.  It is now correctly display the date and time for today, some 31 years after the watch was released by Timex.

If you have any old electronic watches or other devices with dates that don’t reach to the current year, now you know how to set them so they will match up.