probably fixes #19890

asn1.patch

diff --git a/src/encoding/asn1/marshal.go b/src/encoding/asn1/marshal.go
index 3e85651ffd..bea440dcd1 100644
--- a/src/encoding/asn1/marshal.go
+++ b/src/encoding/asn1/marshal.go
@@ -384,26 +384,7 @@ func appendTimeCommon(dst []byte, t time.Time) []byte {
 	dst = appendTwoDigits(dst, min)
 	dst = appendTwoDigits(dst, sec)
 
-	_, offset := t.Zone()
-
-	switch {
-	case offset/60 == 0:
-		return append(dst, 'Z')
-	case offset > 0:
-		dst = append(dst, '+')
-	case offset < 0:
-		dst = append(dst, '-')
-	}
-
-	offsetMinutes := offset / 60
-	if offsetMinutes < 0 {
-		offsetMinutes = -offsetMinutes
-	}
-
-	dst = appendTwoDigits(dst, offsetMinutes/60)
-	dst = appendTwoDigits(dst, offsetMinutes%60)
-
-	return dst
+	return append(dst, 'Z')
 }
 
 func stripTagAndLength(in []byte) []byte {
@@ -419,7 +400,7 @@ func makeBody(value reflect.Value, params fieldParameters) (e encoder, err error
 	case flagType:
 		return bytesEncoder(nil), nil
 	case timeType:
-		t := value.Interface().(time.Time)
+		t := value.Interface().(time.Time).UTC()
 		if params.timeType == TagGeneralizedTime || outsideUTCRange(t) {
 			return makeGeneralizedTime(t)
 		}
@@ -606,7 +587,7 @@ func makeField(v reflect.Value, params fieldParameters) (e encoder, err error) {
 			tag = params.stringType
 		}
 	case TagUTCTime:
-		if params.timeType == TagGeneralizedTime || outsideUTCRange(v.Interface().(time.Time)) {
+		if params.timeType == TagGeneralizedTime || outsideUTCRange(v.Interface().(time.Time).UTC()) {
 			tag = TagGeneralizedTime
 		}
 	}
diff --git a/src/encoding/asn1/marshal_test.go b/src/encoding/asn1/marshal_test.go
index 4f755a1f39..0405a3d9ee 100644
--- a/src/encoding/asn1/marshal_test.go
+++ b/src/encoding/asn1/marshal_test.go
@@ -87,6 +87,7 @@ type numericStringTest struct {
 type testSET []int
 
 var PST = time.FixedZone("PST", -8*60*60)
+var CET = time.FixedZone("CET", +1*60*60)
 
 type marshalTest struct {
 	in  interface{}
@@ -118,9 +119,12 @@ var marshalTests = []marshalTest{
 	{flagTest{false}, "3000"},
 	{time.Unix(0, 0).UTC(), "170d3730303130313030303030305a"},
 	{time.Unix(1258325776, 0).UTC(), "170d3039313131353232353631365a"},
-	{time.Unix(1258325776, 0).In(PST), "17113039313131353134353631362d30383030"},
+	{time.Unix(1258325776, 0).In(PST), "170d3039313131353232353631365a"},
+	{time.Date(1950, 1, 1, 0, 0, 0, 0, CET), "180f31393439313233313233303030305a"},
+	{time.Date(2049, 12, 31, 23, 0, 0, 0, PST), "180f32303530303130313037303030305a"},
 	{farFuture(), "180f32313030303430353132303130315a"},
 	{generalizedTimeTest{time.Unix(1258325776, 0).UTC()}, "3011180f32303039313131353232353631365a"},
+	{generalizedTimeTest{time.Unix(1258325776, 1).UTC()}, "3011180f32303039313131353232353631365a"},
 	{BitString{[]byte{0x80}, 1}, "03020780"},
 	{BitString{[]byte{0x81, 0xf0}, 12}, "03030481f0"},
 	{ObjectIdentifier([]int{1, 2, 3, 4}), "06032a0304"},