diff --git a/cmd/parser/main.go b/cmd/parser/main.go
index b576f5a..cf1f9ec 100644
--- a/cmd/parser/main.go
+++ b/cmd/parser/main.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"encoding/json"
 	"flag"
 	"fmt"
 	"github.com/rejlersembriq/gs2"
@@ -12,6 +11,15 @@ import (
 
 var filename = flag.String("file", "", "File to parse")
 
+func validateTime(g *gs2.GS2) error {
+	for _, ts := range g.TimeSeries {
+		if ts.Start.Add(time.Duration(ts.NoOfValues)*ts.Step) != ts.Stop {
+			return fmt.Errorf("start %q, stop %q step %q doesnt match", ts.Start.Format(time.RFC3339), ts.Stop.Format(time.RFC3339), ts.Step)
+		}
+	}
+	return nil
+}
+
 func main() {
 	flag.Parse()
 
@@ -26,20 +34,20 @@ func main() {
 
 	start := time.Now()
 
-	result, err := gs2.NewDecoder(file).Decode()
-	if err != nil {
-		log.Fatal(err)
+	options := []gs2.DecoderOption{
+		gs2.DecodeValidators(
+			gs2.ValidateNoOfObjects,
+			gs2.ValidateTimeSeriesValues,
+			validateTime,
+		),
 	}
 
-	took := time.Since(start)
-
-	indent, err := json.MarshalIndent(result, "", "    ")
+	_, err = gs2.NewDecoder(file, options...).Decode()
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	fmt.Println("")
-	fmt.Println(string(indent))
+	took := time.Since(start)
 
 	fmt.Printf("Parsing took: %v\n", took)
 }
diff --git a/decode.go b/decode.go
index 6c5c049..5da4070 100644
--- a/decode.go
+++ b/decode.go
@@ -426,6 +426,10 @@ func parseTriplet(val string) (Triplet, error) {
 }
 
 func parseTime(s string) (time.Time, error) {
+	if s == "" {
+		return time.Time{}, nil
+	}
+
 	var modifier time.Duration
 	if strings.Contains(s, "24:00:00") {
 		s = strings.Replace(s, "24:00:00", "00:00:00", 1)