amazing how many give a day and month, but no year.
Counterbalanced by the sites that were, by amazing coincidence, updated only just today. As if they knew you were coming. Uhm, sorry, site owner, but we're looking for the date of your last substantive revision, not the last time the php compiled.
I used to have <address> lines with month and year, but gave it up as too 1998 :(