Decode CBOR time tags to interface{} as RFC 3339 timestamps.

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/cbor/internal/modes/appendixa_test.go

@@ -300,17 +300,15 @@ func TestAppendixA(t *testing.T) {
 				reasonByteString,
 				reasonTimeToInterface,
 			},
-			fixme: "decoding of tagged time into interface{} must produce RFC3339 timestamp compatible with JSON, not time.Time",
 		},
 		{
 			example: hex("c11a514b67b0"),
-			decoded: "2013-03-21T16:04:00Z",
+			decoded: "2013-03-21T20:04:00Z",
-			encoded: hex("54323031332d30332d32315431363a30343a30305a"),
+			encoded: hex("54323031332d30332d32315432303a30343a30305a"),
 			reasons: []string{
 				reasonByteString,
 				reasonTimeToInterface,
 			},
-			fixme: "decoding of tagged time into interface{} must produce RFC3339 timestamp compatible with JSON, not time.Time",
 		},
 		{
 			example: hex("c1fb41d452d9ec200000"),
@@ -320,7 +318,6 @@ func TestAppendixA(t *testing.T) {
 				reasonByteString,
 				reasonTimeToInterface,
 			},
-			fixme: "decoding of tagged time into interface{} must produce RFC3339 timestamp compatible with JSON, not time.Time",
 		},
 		{
 			example: hex("d74401020304"),

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/cbor/internal/modes/decode.go

@@ -85,6 +85,9 @@ var Decode cbor.DecMode = func() cbor.DecMode {
 		// instead of the default, a cbor.Tag representing a (number, content) pair.
 		UnrecognizedTagToAny: cbor.UnrecognizedTagContentToAny,
 
+		// Decode time tags to interface{} as strings containing RFC 3339 timestamps.
+		TimeTagToAny: cbor.TimeTagToRFC3339Nano,
+
 		// For parity with JSON, strings can be decoded into time.Time if they are RFC 3339
 		// timestamps.
 		ByteStringToTime: cbor.ByteStringToTimeAllowed,

staging/src/k8s.io/apimachinery/pkg/runtime/serializer/cbor/internal/modes/decode_test.go

@@ -647,7 +647,6 @@ func TestDecode(t *testing.T) {
 				name:          "tag 0 RFC3339 text string",
 				in:            hex("c074323030362d30312d30325431353a30343a30355a"), // 0("2006-01-02T15:04:05Z")
 				want:          "2006-01-02T15:04:05Z",
-				fixme:         "decoding RFC3339 text string tagged with 0 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
@@ -668,63 +667,54 @@ func TestDecode(t *testing.T) {
 				name:          "tag 1 timestamp unsigned integer",
 				in:            hex("c11a43b940e5"), // 1(1136214245)
 				want:          "2006-01-02T15:04:05Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with float16 value",
 				in:            hex("c1f93c00"), // 1(1.0_1)
 				want:          "1970-01-01T00:00:01Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with float32 value",
 				in:            hex("c1fa3f800000"), // 1(1.0_2)
 				want:          "1970-01-01T00:00:01Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with float64 value",
 				in:            hex("c1fb3ff0000000000000"), // 1(1.0_3)
 				want:          "1970-01-01T00:00:01Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with a five digit year",
 				in:            hex("c11b0000003afff44181"), // 1(253402300801)
 				want:          "10000-01-01T00:00:01Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
+				assertOnError: assertErrorMessage("cbor: decoded time cannot be represented in RFC3339 format with sub-second precision: Time.MarshalText: year outside of range [0,9999]"),
-				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with a negative integer value",
 				in:            hex("c120"), // 1(-1)
 				want:          "1969-12-31T23:59:59Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with a negative float16 value",
 				in:            hex("c1f9bc00"), // 1(-1.0_1)
 				want:          "1969-12-31T23:59:59Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with a negative float32 value",
 				in:            hex("c1fabf800000"), // 1(-1.0_2)
 				want:          "1969-12-31T23:59:59Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{
 				name:          "tag 1 with a negative float64 value",
 				in:            hex("c1fbbff0000000000000"), // 1(-1.0_3)
 				want:          "1969-12-31T23:59:59Z",
-				fixme:         "decoding cbor data tagged with 1 produces time.Time instead of RFC3339 timestamp string",
 				assertOnError: assertNilError,
 			},
 			{