1 files changed, 12 insertions, 0 deletions
diff --git a/Lib/email/_parseaddr.py b/Lib/email/_parseaddr.py
index 81913a3824..ac2e524401 100644
--- a/Lib/email/_parseaddr.py
+++ b/Lib/email/_parseaddr.py
@@ -107,6 +107,18 @@ def parsedate_tz(data):
         tss = int(tss)
     except ValueError:
         return None
+    # Check for a yy specified in two-digit format, then convert it to the
+    # appropriate four-digit format, according to the POSIX standard. RFC 822
+    # calls for a two-digit yy, but RFC 2822 (which obsoletes RFC 822)
+    # mandates a 4-digit yy. For more information, see the documentation for
+    # the time module.
+    if yy < 100:
+        # The year is between 1969 and 1999 (inclusive).
+        if yy > 68:
+            yy += 1900
+        # The year is between 2000 and 2068 (inclusive).
+        else:
+            yy += 2000
     tzoffset = None
     tz = tz.upper()
     if tz in _timezones: