added discovery / timestampe model

modules/timestamp/model/timestamp.go

@@ -0,0 +1,37 @@
+package timestamp
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+)
+
+type Timestamp time.Time
+
+func (t Timestamp) MarshalJSON() ([]byte, error) {
+	ts := time.Time(t).Unix()
+	stamp := fmt.Sprint(ts * 1000)
+	return []byte(stamp), nil
+}
+
+func (t *Timestamp) UnmarshalJSON(b []byte) error {
+	ts, err := strconv.Atoi(string(b))
+	if err != nil {
+		return err
+	}
+	*t = Timestamp(time.Unix(int64(ts)/1000, 0))
+
+	return nil
+}
+
+func (t Timestamp) String() string {
+	return time.Time(t).String()
+}
+
+func Now() Timestamp {
+	return Timestamp(time.Now())
+}
+
+func Date(year int, month time.Month, day int) Timestamp {
+	return Timestamp(time.Date(year, month, day, 0, 0, 0, 0, time.UTC))
+}