[Ocamlnet-devel] Interpretation of 2 and 3 digit years

[Patrick M D. <pa...@wa...>]

One of the modifications in RFC 2822 (Internet Message Format) is explicit
instructions on the interpretation of two or three year date formats:

   Where a two or three digit year occurs in a date, the year is to be
   interpreted as follows: If a two digit year is encountered whose
   value is between 00 and 49, the year is interpreted by adding 2000,
   ending up with a value between 2000 and 2049.  If a two digit year is
   encountered with a value between 50 and 99, or any three digit year
   is encountered, the year is interpreted by adding 1900.

The Netdate code implements a slightly different heuristic:

  if y >= 100 then     y
  else if y < 69 then (2000 + y)
  else                (1900 + y)

which is basically the same as C version that this code is based on.

I'm in favor of the rules described in RFC 2822 although I would have
limited the adjustment to a tighter bound (like 150 instead of 999).

Is anyone aware of other intrepretations that we might need to follow? If
not, it is probably best to adopt the RFC 2822 semantics.

Patrick