Timestamp for marshal/unmarshal json from javascript timestamp

timestamp.go

package timestamp

import (
	"strconv"
	"time"
)

// Declare as *Timestamp to get it worked else it will use default time string format.
type Timestamp struct {
	time.Time
}

func (t *Timestamp) MarshalJSON() ([]byte, error) {
	ts := t.Time.UnixNano() / 1000

	return []byte(strconv.Itoa(int(ts))), nil
}

func (t *Timestamp) UnmarshalJSON(b []byte) error {
	ts, err := strconv.Atoi(string(b))
	if err != nil {
		return err
	}

	ts64 := int64(ts)
	t.Time = time.Unix(ts64/int64(time.Millisecond), ts64%int64(time.Millisecond)*1000)
	return nil
}

func (t *Timestamp) IsZero() bool {
	return t.Second() == 0
}