Patch by Mike Meyer:

gvanrossum · gvanrossum · commit db01ee0e22c3 · 1998-12-23T22:22:10.000Z
Extended the rfc822 parsedate routines to handle the cases they failed
on in an archive of ~37,000 messages.  I believe the changes are
compatible, in that all previously correct parsing are still correct.

[I still see problems with some messages, but no showstoppers.]
diff --git a/Lib/rfc822.py b/Lib/rfc822.py
@@ -748,9 +748,11 @@ def dump_address_pair(pair):
 
 # Parse a date field
 
-_monthnames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul',
-               'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
-_daynames = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
+_monthnames = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul',
+               'aug', 'sep', 'oct', 'nov', 'dec',
+	       'january', 'february', 'march', 'april', 'may', 'june', 'july',
+               'august', 'september', 'october', 'november', 'december']
+_daynames = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
 
 # The timezone table does not include the military time zones defined
 # in RFC822, other than Z.  According to RFC1123, the description in
@@ -773,7 +775,7 @@ def parsedate_tz(data):
     Accounts for military timezones.
     """
     data = string.split(data)
-    if data[0][-1] == ',' or data[0] in _daynames:
+    if data[0][-1] in (',', '.') or string.lower(data[0]) in _daynames:
         # There's a dayname here. Skip it
         del data[0]
     if len(data) == 3: # RFC 850 date, deprecated
@@ -791,11 +793,23 @@ def parsedate_tz(data):
         return None
     data = data[:5]
     [dd, mm, yy, tm, tz] = data
+    mm = string.lower(mm)
     if not mm in _monthnames:
-        dd, mm, yy, tm, tz = mm, dd, tm, yy, tz
+        dd, mm = mm, string.lower(dd)
         if not mm in _monthnames:
             return None
     mm = _monthnames.index(mm)+1
+    if dd[-1] == ',':
+	dd = dd[:-1]
+    i = string.find(yy, ':')
+    if i > 0:
+	yy, tm = tm, yy
+    if yy[-1] == ',':
+	yy = yy[:-1]
+    if yy[0] not in string.digits:
+	yy, tz = tz, yy
+    if tm[-1] == ',':
+	tm = tm[:-1]
     tm = string.splitfields(tm, ':')
     if len(tm) == 2:
         [thh, tmm] = tm
