Quote:

>Apparently, "windowing" (i.e., assuming a two digit date is in whatever

>century it is 'logical for it to be in) has been patented:

><http://news.cnet.com/news/0-1009-200-1426450.html>

>Windowing is officially part of Common Lisp, though.

Someone asked me where this is defined. From the Hyperspec

<http://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node232.html>

From 25.4.1. Time Functions, and the definition of encode-universal-time:

Decoded Time format represents calendar time as a number of components:

Second: an integer between 0 and 59, inclusive.

Minute: an integer between 0 and 59, inclusive.

Hour: an integer between 0 and 23, inclusive.

Date: an integer between 1 and 31, inclusive (the upper limit actually

depends on the month and year, of course).

Month: an integer between 1 and 12, inclusive; 1 means January, 12 means

December.

Year: an integer indicating the year A.D. However, if this integer is

between 0 and 99, the ``obvious'' year is used; more precisely, that year is

assumed that is equal to the integer modulo 100 and within fifty years of

the current year (inclusive backwards and exclusive forwards). Thus, in the

year 1978, year 28 is 1928 but year 27 is 2027. (Functions that return time

in this format always return a full year number.)