diff --git a/README.md b/README.md
index eefc1f6..5429b13 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,7 @@ func main() {
     // UNIX Time is faster and smaller than most timestamps
     // If you set zerolog.TimeFieldFormat to an empty string,
     // logs will write with UNIX time
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 
     log.Print("hello world")
 }
@@ -76,7 +76,7 @@ import (
 )
 
 func main() {
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 
     log.Debug().
         Str("Scale", "833 cents").
@@ -102,7 +102,7 @@ import (
 )
 
 func main() {
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 
     log.Info().Msg("hello world")
 }
@@ -138,7 +138,7 @@ import (
 )
 
 func main() {
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
     debug := flag.Bool("debug", false, "sets log level to debug")
 
     flag.Parse()
@@ -189,7 +189,7 @@ import (
 )
 
 func main() {
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 
     log.Log().
         Str("foo", "bar").
@@ -215,7 +215,7 @@ func main() {
     err := errors.New("A repo man spends his life getting into tense situations")
     service := "myservice"
 
-    zerolog.TimeFieldFormat = ""
+    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 
     log.Fatal().
         Err(err).
@@ -474,9 +474,8 @@ Some settings can be changed and will by applied to all loggers:
 * `zerolog.LevelFieldName`: Can be set to customize level field name.
 * `zerolog.MessageFieldName`: Can be set to customize message field name.
 * `zerolog.ErrorFieldName`: Can be set to customize `Err` field name.
-* `zerolog.TimeFieldFormat`: Can be set to customize `Time` field value formatting. If set with an empty string, times are formated as UNIX timestamp.
-    // DurationFieldUnit defines the unit for time.Duration type fields added
-    // using the Dur method.
+* `zerolog.TimeFieldFormat`: Can be set to customize `Time` field value formatting. If set with `zerolog.TimeFormatUnix` or `zerolog.TimeFormatUnixMs`, times are formated as UNIX timestamp.
+* DurationFieldUnit defines the unit for time.Duration type fields added using the Dur method.
 * `DurationFieldUnit`: Sets the unit of the fields added by `Dur` (default: `time.Millisecond`).
 * `DurationFieldInteger`: If set to true, `Dur` fields are formatted as integers instead of floats.
 * `ErrorHandler`: Called whenever zerolog fails to write an event on its output. If not set, an error is printed on the stderr. This handler must be thread safe and non-blocking.
diff --git a/benchmark_test.go b/benchmark_test.go
index 4ae9d49..84e7370 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -234,7 +234,7 @@ func BenchmarkLogFieldType(b *testing.B) {
 
 func BenchmarkContextFieldType(b *testing.B) {
 	oldFormat := TimeFieldFormat
-	TimeFieldFormat = ""
+	TimeFieldFormat = TimeFormatUnix
 	defer func() { TimeFieldFormat = oldFormat }()
 	bools := []bool{true, false, true, false, true, false, true, false, true, false}
 	ints := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
diff --git a/globals.go b/globals.go
index 2024137..c1fa37c 100644
--- a/globals.go
+++ b/globals.go
@@ -6,6 +6,16 @@ import (
 )
 import "sync/atomic"
 
+const (
+	// TimeFormatUnix defines a time format that makes time fields to be
+	// serialized as Unix timestamp integers.
+	TimeFormatUnix = ""
+
+	// TimeFormatUnix defines a time format that makes time fields to be
+	// serialized as Unix timestamp integers in milliseconds.
+	TimeFormatUnixMs = "UNIXMS"
+)
+
 var (
 	// TimestampFieldName is the field name used for the timestamp field.
 	TimestampFieldName = "time"
@@ -46,9 +56,9 @@ var (
 		return err
 	}
 
-	// TimeFieldFormat defines the time format of the Time field type.
-	// If set to an empty string, the time is formatted as an UNIX timestamp
-	// as integer.
+	// TimeFieldFormat defines the time format of the Time field type. If set to
+	// TimeFormatUnix or TimeFormatUnixMs, the time is formatted as an UNIX
+	// timestamp as integer.
 	TimeFieldFormat = time.RFC3339
 
 	// TimestampFunc defines the function called to generate a timestamp.
diff --git a/internal/json/time.go b/internal/json/time.go
index 739afff..18dea5e 100644
--- a/internal/json/time.go
+++ b/internal/json/time.go
@@ -5,11 +5,20 @@ import (
 	"time"
 )
 
+const (
+	// Import from zerolog/global.go
+	timeFormatUnix   = ""
+	timeFormatUnixMs = "UNIXMS"
+)
+
 // AppendTime formats the input time with the given format
 // and appends the encoded string to the input byte slice.
 func (e Encoder) AppendTime(dst []byte, t time.Time, format string) []byte {
-	if format == "" {
+	switch format {
+	case timeFormatUnix:
 		return e.AppendInt64(dst, t.Unix())
+	case timeFormatUnixMs:
+		return e.AppendInt64(dst, t.UnixNano()/1000000)
 	}
 	return append(t.AppendFormat(append(dst, '"'), format), '"')
 }
@@ -17,8 +26,11 @@ func (e Encoder) AppendTime(dst []byte, t time.Time, format string) []byte {
 // AppendTimes converts the input times with the given format
 // and appends the encoded string list to the input byte slice.
 func (Encoder) AppendTimes(dst []byte, vals []time.Time, format string) []byte {
-	if format == "" {
+	switch format {
+	case timeFormatUnix:
 		return appendUnixTimes(dst, vals)
+	case timeFormatUnixMs:
+		return appendUnixMsTimes(dst, vals)
 	}
 	if len(vals) == 0 {
 		return append(dst, '[', ']')
@@ -49,6 +61,21 @@ func appendUnixTimes(dst []byte, vals []time.Time) []byte {
 	return dst
 }
 
+func appendUnixMsTimes(dst []byte, vals []time.Time) []byte {
+	if len(vals) == 0 {
+		return append(dst, '[', ']')
+	}
+	dst = append(dst, '[')
+	dst = strconv.AppendInt(dst, vals[0].UnixNano()/1000000, 10)
+	if len(vals) > 1 {
+		for _, t := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), t.UnixNano()/1000000, 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 // AppendDuration formats the input duration with the given unit & format
 // and appends the encoded string to the input byte slice.
 func (e Encoder) AppendDuration(dst []byte, d time.Duration, unit time.Duration, useInt bool) []byte {