Revert "[3.13] gh-120713: Normalize year with century for datetime.strftime (GH-120820) (GH-121144)" (GH-122408)

This reverts commit 009618f1125838af3c4afc772f2593637766fd45.

1 files changed, 12 insertions, 20 deletions

diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index ca804fe..d0ee974 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -1697,26 +1697,18 @@ class TestDate(HarmlessMixedComparison, unittest.TestCase):
         self.assertTrue(self.theclass.max)
 
     def test_strftime_y2k(self):
-        # Test that years less than 1000 are 0-padded; note that the beginning
-        # of an ISO 8601 year may fall in an ISO week of the year before, and
-        # therefore needs an offset of -1 when formatting with '%G'.
-        dataset = (
-            (1, 0),
-            (49, -1),
-            (70, 0),
-            (99, 0),
-            (100, -1),
-            (999, 0),
-            (1000, 0),
-            (1970, 0),
-        )
-        for year, offset in dataset:
-            for specifier in 'YG':
-                with self.subTest(year=year, specifier=specifier):
-                    d = self.theclass(year, 1, 1)
-                    if specifier == 'G':
-                        year += offset
-                    self.assertEqual(d.strftime(f"%{specifier}"), f"{year:04d}")
+        for y in (1, 49, 70, 99, 100, 999, 1000, 1970):
+            d = self.theclass(y, 1, 1)
+            # Issue 13305:  For years < 1000, the value is not always
+            # padded to 4 digits across platforms.  The C standard
+            # assumes year >= 1900, so it does not specify the number
+            # of digits.
+            if d.strftime("%Y") != '%04d' % y:
+                # Year 42 returns '42', not padded
+                self.assertEqual(d.strftime("%Y"), '%d' % y)
+                # '0042' is obtained anyway
+                if support.has_strftime_extensions:
+                    self.assertEqual(d.strftime("%4Y"), '%04d' % y)
 
     def test_replace(self):
         cls = self.theclass