Add RFC3339, RFC3339Nano and update docs to include 'nano' (#736)

zapcore/encoder.go

@@ -118,11 +118,30 @@ func ISO8601TimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
 	enc.AppendString(t.Format("2006-01-02T15:04:05.000Z0700"))
 }
 
-// UnmarshalText unmarshals text to a TimeEncoder. "iso8601" and "ISO8601" are
-// unmarshaled to ISO8601TimeEncoder, "millis" is unmarshaled to
-// EpochMillisTimeEncoder, and anything else is unmarshaled to EpochTimeEncoder.
+// RFC3339TimeEncoder serializes a time.Time to an RFC3339-formatted string.
+func RFC3339TimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	enc.AppendString(t.Format(time.RFC3339))
+}
+
+// RFC3339NanoTimeEncoder serializes a time.Time to an RFC3339-formatted string
+// with nanosecond precision.
+func RFC3339NanoTimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	enc.AppendString(t.Format(time.RFC3339Nano))
+}
+
+// UnmarshalText unmarshals text to a TimeEncoder.
+// "rfc3339nano" and "RFC3339Nano" are unmarshaled to RFC3339NanoTimeEncoder.
+// "rfc3339" and "RFC3339" are unmarshaled to RFC3339TimeEncoder.
+// "iso8601" and "ISO8601" are unmarshaled to ISO8601TimeEncoder.
+// "millis" is unmarshaled to EpochMillisTimeEncoder.
+// "nanos" is unmarshaled to EpochNanosEncoder.
+// Anything else is unmarshaled to EpochTimeEncoder.
 func (e *TimeEncoder) UnmarshalText(text []byte) error {
 	switch string(text) {
+	case "rfc3339nano", "RFC3339Nano":
+		*e = RFC3339NanoTimeEncoder
+	case "rfc3339", "RFC3339":
+		*e = RFC3339TimeEncoder
 	case "iso8601", "ISO8601":
 		*e = ISO8601TimeEncoder
 	case "millis":

zapcore/encoder_test.go

@@ -540,6 +540,10 @@ func TestTimeEncoders(t *testing.T) {
 		{"nanos", int64(100050005000)},
 		{"", 100.050005},
 		{"something-random", 100.050005},
+		{"rfc3339", "1970-01-01T00:01:40Z"},
+		{"RFC3339", "1970-01-01T00:01:40Z"},
+		{"rfc3339nano", "1970-01-01T00:01:40.050005Z"},
+		{"RFC3339Nano", "1970-01-01T00:01:40.050005Z"},
 	}
 
 	for _, tt := range tests {