Use SYSLOG_TIMESTAMP instead of TIMESTAMP and format as micros

Author: arianvp

journal.go

@@ -133,7 +133,8 @@ func (h *Handler) Handle(ctx context.Context, r slog.Record) error {
 	// NOTE: journald does its own timestamping. Lets just ignore
 	// NOTE: slogtest requires this. grrr
 	if !r.Time.IsZero() {
-		buf = h.appendKV(buf, "TIMESTAMP", []byte(strconv.Itoa(int(r.Time.Unix()))))
+		timestampStr := strconv.FormatInt(r.Time.UnixMicro(), 10)
+		buf = h.appendKV(buf, "SYSLOG_TIMESTAMP", []byte(timestampStr))
 	}
 
 	buf = append(buf, h.preformatted...)

journal_test.go

@@ -111,7 +111,7 @@ func TestBasicFunctionality(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	v, ok := kv["TIMESTAMP"]
+	v, ok := kv["SYSLOG_TIMESTAMP"]
 	if ok {
 		t.Error("Unexpected timestamp", v, kv)
 	}
@@ -216,7 +216,7 @@ func TestSlogtest(t *testing.T) {
 				k = slog.MessageKey
 			case "PRIORITY":
 				k = slog.LevelKey
-			case "TIMESTAMP":
+			case "SYSLOG_TIMESTAMP":
 				k = slog.TimeKey
 			}
 			m[k] = v