1926..1989 Showa 1..64 (reign of japanese emperor Hirohito)
1989..today Heisei 1..today (reign of japanese emperor Akihito)
Ie. for Gregorian and Heisei calendars set LeapYearOffset=0, for Showa calendar set LeapYearOffset=1 (as suggested in the CPC magazine). Anyways, the article recommends to use Gregorian calendar, ie. using year=86 for 1986, so, if the battery survived, it wrapped to year=00 in year 2000.
== Commercial versions ==