Extensive research by Peter-Paul Koch on the complications with HTML5’s draft spec for the
time element on the subject of historical dates.
Of course, HTML5 actually has a solution for this: don’t. They are very specific about
time not being available for pre-Gregorian dates, but ppk’s proposal is interesting nonetheless, and I believe it is well worth considering adding the
calendar attribute to
time, and being somewhat flexible about the input. The problem with flexible input is of course that people misuse it.