date_format function incorrect

[lide-reed]

Describe the bug
mysql> select date_format("2019-03-04 22:23:00", '%W %w');
+---------------------------------------------+
| date_format('2019-03-04 22:23:00', '%W %w') |
+---------------------------------------------+
| %2 %10 |
+---------------------------------------------+
1 row in set (0.08 sec)

To Reproduce
mysql> select date_format("2019-03-04 22:23:00", '%W %w');
+---------------------------------------------+
| date_format('2019-03-04 22:23:00', '%W %w') |
+---------------------------------------------+
| %2 %10 |
+---------------------------------------------+
1 row in set (0.08 sec)

Expected behavior
mysql> select date_format("2019-03-04 22:23:00", '%W %w');
+---------------------------------------------+
| date_format('2019-03-04 22:23:00', '%W %w') |
+---------------------------------------------+
| Monday 1 |
+---------------------------------------------+
1 row in set (0.04 sec)