10,000 day calender that chrysler used

There used to be a web site that would figure the dates. I don't know if there is another one,or if there is a formula to figure the dates.

i have a calender in one of Galens, books, don't know if it is the same but it is the one i use, and it works pretty good i look something up for you if you need me too.
Blessings, Frank