Re: even elder races get tired of waiting

[Jude DaShiell <jdashiel@panix.com>]

Use of cal with a month number and a year number to get a weekday of a 
particular date can make work a little easier.
This is for really long time periods and only inside the gregorian 
calendar constraints since outside of those constraints things get really 
wild as a result of compound errors.
With that weekday in mind subtracting a year when you won't land in a leap 
year or adding a year when you won't land in a leap year, subtract or add 
one weekday to get the correct weekday for that date in those years.  If 
you will land in a leap year, subtract or add two weekdays to get the 
correct weekday.  Modulus the weekday by 7 to keep it in whichever range 
you prefer to use..
That can get you to the correct forest, then it's a matter of smaller 
subtraction or addition within a year to get you your exact length.