In the Templates documentation, the Now tag's format character n is indicated as creating a RFC 822 formatted date., but the example output 'Thu, 21 Dec 2000 16:01:07 +0200' is an RFC 2822 date format:
RFC 822 section 5.1 defines date as
date = 1*2DIGIT month 2DIGIT ; day month year
; e.g. 20 Jun 82
which only has 2-digits year notation.
On the other hand, RFC 2822 section 3.3 defines date as
date = day month year
year = 4*DIGIT / obs-year
month = (FWS month-name FWS) / obs-month
month-name = "Jan" / "Feb" / "Mar" / "Apr" /
"May" / "Jun" / "Jul" / "Aug" /
"Sep" / "Oct" / "Nov" / "Dec"
day = ([FWS] 1*2DIGIT) / obs-day
with year being either 4 digits or 2 digits (obs-year refers to RFC 822 year formatting)
