diff --git a/types/format_test.go b/types/format_test.go
index 493ac31e75..d4434dc301 100644
--- a/types/format_test.go
+++ b/types/format_test.go
@@ -62,7 +62,7 @@ func (s *testTimeSuite) TestTimeFormatMethod(c *C) {
 			// %W %w %a is not compatible in this case because Week() use GoTime() currently.
 			"0000-01-00 00:00:00.123456",
 			`%b %M %m %c %D %d %e %j %k %h %i %p %r %T %s %f %U %u %V %v %a %W %w %X %x %Y %y %%`,
-			`Jan January 01 1 0th 00 0 000 0 12 00 AM 12:00:00 AM 00:00:00 00 123456 00 00 00 52 Sun Sunday 0 4294967295 4294967295 0000 00 %`,
+			`Jan January 01 1 0th 00 0 000 0 12 00 AM 12:00:00 AM 00:00:00 00 123456 00 00 00 52 Fri Friday 5 4294967295 4294967295 0000 00 %`,
 		},
 	}
 	for i, t := range tblDate {
diff --git a/types/mytime.go b/types/mytime.go
index 5ee12ec20a..733571f023 100644
--- a/types/mytime.go
+++ b/types/mytime.go
@@ -70,8 +70,9 @@ func (t MysqlTime) Microsecond() int {
 func (t MysqlTime) Weekday() gotime.Weekday {
 	// TODO: Consider time_zone variable.
 	t1, err := t.GoTime(gotime.Local)
+	// allow invalid dates
 	if err != nil {
-		return 0
+		return t1.Weekday()
 	}
 	return t1.Weekday()
 }
diff --git a/types/mytime_test.go b/types/mytime_test.go
index f2897c8789..76a32f4b40 100644
--- a/types/mytime_test.go
+++ b/types/mytime_test.go
@@ -271,3 +271,19 @@ func (s *testMyTimeSuite) TestAddDate(c *C) {
 		c.Assert(res.Year(), Equals, t.year+t.ot.Year())
 	}
 }
+
+func (s *testMyTimeSuite) TestWeekday(c *C) {
+	tests := []struct {
+		Input  MysqlTime
+		Expect string
+	}{
+		{MysqlTime{2019, 01, 01, 0, 0, 0, 0}, "Tuesday"},
+		{MysqlTime{2019, 02, 31, 0, 0, 0, 0}, "Sunday"},
+		{MysqlTime{2019, 04, 31, 0, 0, 0, 0}, "Wednesday"},
+	}
+
+	for _, tt := range tests {
+		weekday := tt.Input.Weekday()
+		c.Check(weekday.String(), Equals, tt.Expect)
+	}
+}