Is there a web site with a magic decoder ring to transform from the 10,000 day calendar into mnth/day/yr?
who has the free decoder ring?

The only website that had that info (lightningjar.com) has been shutdown for some time.

Galen's White Books have the '67-'74 decoder.

I think I have it. The first day in the 10,000 day calendar is July 29, 1961. If you use an Excel spreadsheet function 'datevalue' it returns the serial number of July 28, 1961 (the day before) as 22490. With July 29, 1961 being 0001, if you add this to 22490 and use the Excel 'month', 'day', and 'year' functions, you get 7, 29, 1961 respectively. I tried this with some dates from the 1970 parts book and if you add the 10,000 day date to 22490 and apply the Excel functions, you get agreement every time.

Here is an xls worksheet I did in 2003. You will need Excel to use it.

Excel Viewer

Wow!! Neat

For us "Office challenged" can you explain how to use the worksheet?

Type the 10,000 day calendar date in cell A4 and press 'enter'.

this is an awesome addition.. thank you for your hard work on this, it has helped me already.

That's nice Snoopy.

heres a link for annual calendar, good for part date codes, etc
http://www.timeanddate.com/calendar/cust...;doy=1&df=1

Here's a neat calculator from Maxwedge.com

http://maxwedge.com/articles/10k.php

It also helps to have a Julian date calendar, if you have a date code like '1368', which is the 136th day of '68. Try:

http://www.imap.mesacounty.us/GPS_Survey/RINEX%20TIME/julian-calendar.pdf

There are two calendars, one for leap years, and one for others. Of course, leap years are the ones evenly divisible by 4, such as 1968 and 1972.

I too did a search for 10,000 day calendar and found this thread. The excel sheet doesnt work for me but the max wedge site did.
Fender tag says may 31st 1973.
4282 on my transmission works out to April 18th, 1973
142-3 on my thermoquad works out to May 22nd, 1973

However my block i dated 6-10-76