diff --git a/README.md b/README.md
index e800e7e5..4ea55fd5 100644
--- a/README.md
+++ b/README.md
@@ -564,6 +564,7 @@ The log file of Ayd is stored in [JSON Lines](https://jsonlines.org/) format, en
 Each record has at least 4 fields.
 
 - `time` when status check started, in [RFC3339 format](https://tools.ietf.org/html/rfc3339) like `2001-02-30T16:05:06+00:00`.
+  Ayd can parse some variant formats like `2001-02-03 16:05:06+0000` or `20010203_160506Z`, and the UNIX time seconds.
 
 - `status` of the record that `HEALTHY`, `DEGRADE`, `FAILURE`, `UNKNOWN`, or `ABORTED`.
 
diff --git a/lib-ayd/record.go b/lib-ayd/record.go
index 58a8addf..e8916429 100644
--- a/lib-ayd/record.go
+++ b/lib-ayd/record.go
@@ -120,10 +120,15 @@ func (r *Record) UnmarshalJSON(data []byte) error {
 	if value, ok := raw["time"]; !ok {
 		return ayderr.New(ErrInvalidRecord, nil, "invalid record: time: missing required field")
 	} else {
-		if s, ok := value.(string); !ok {
-			return ayderr.New(ErrInvalidRecord, nil, "invalid record: time: should be a string")
-		} else if r.Time, err = ParseTime(s); err != nil {
-			return ayderr.New(ErrInvalidRecord, err, "invalid record: time")
+		switch v := value.(type) {
+		case float64:
+			r.Time = time.UnixMilli(int64(v * 1000))
+		case string:
+			if r.Time, err = ParseTime(v); err != nil {
+				return ayderr.New(ErrInvalidRecord, err, "invalid record: time")
+			}
+		default:
+			return ayderr.New(ErrInvalidRecord, nil, "invalid record: time: should be a string or a number")
 		}
 		delete(raw, "time")
 	}
diff --git a/lib-ayd/record_test.go b/lib-ayd/record_test.go
index ce4d08d4..d72d9e7b 100644
--- a/lib-ayd/record_test.go
+++ b/lib-ayd/record_test.go
@@ -54,6 +54,7 @@ func TestRecord(t *testing.T) {
 
 	tests := []struct {
 		String string
+		Encode string
 		Record ayd.Record
 		Error  string
 	}{
@@ -88,7 +89,8 @@ func TestRecord(t *testing.T) {
 			},
 		},
 		{
-			String: `{"time":"2021-01-02T15:04:05+09:00", "status":"DEGRADE", "latency":1027.890, "target":"dummy:"}`,
+			String: `{"time":"2021-01-02 15:04:05+09:00", "status":"DEGRADE", "latency":1027.890, "target":"dummy:"}`,
+			Encode: `{"time":"2021-01-02T15:04:05+09:00", "status":"DEGRADE", "latency":1027.890, "target":"dummy:"}`,
 			Record: ayd.Record{
 				Time:    time.Date(2021, 1, 2, 15, 4, 5, 0, tokyo),
 				Target:  &ayd.URL{Scheme: "dummy"},
@@ -97,6 +99,17 @@ func TestRecord(t *testing.T) {
 				Latency: 1027890 * time.Microsecond,
 			},
 		},
+		{
+			String: `{"time":1641135845, "status":"HEALTHY", "latency":12.345, "target":"dummy:"}`,
+			Encode: `{"time":"2022-01-02T15:04:05Z", "status":"HEALTHY", "latency":12.345, "target":"dummy:"}`,
+			Record: ayd.Record{
+				Time:    time.Date(2022, 1, 2, 15, 4, 5, 0, time.UTC),
+				Target:  &ayd.URL{Scheme: "dummy"},
+				Status:  ayd.StatusHealthy,
+				Message: "",
+				Latency: 12345 * time.Microsecond,
+			},
+		},
 		{
 			String: `{"time":"2021-01-02T15:04:05+09:00", "status":"HEALTHY", "latency":123abc, "target":"ping:example.com", "message":"hello world"}`,
 			Error:  "invalid record: invalid character 'a' after object key:value pair",
@@ -122,8 +135,8 @@ func TestRecord(t *testing.T) {
 			Error:  `invalid record: time: missing required field`,
 		},
 		{
-			String: `{"time":123, "status":"HEALTHY", "latency":123.456, "target":"ping:example.com", "message":"hello world"}`,
-			Error:  `invalid record: time: should be a string`,
+			String: `{"time":{}, "status":"HEALTHY", "latency":123.456, "target":"ping:example.com", "message":"hello world"}`,
+			Error:  `invalid record: time: should be a string or a number`,
 		},
 		{
 			String: `{"time":"2021-01-02T15:04:05+09:00", "status":null, "latency":123.456, "target":"ping:example.com", "message":"hello world"}`,
@@ -209,8 +222,12 @@ func TestRecord(t *testing.T) {
 			t.Errorf("unexpected extra\n%s", diff)
 		}
 
-		if tt.Record.String() != tt.String {
-			t.Errorf("expected: %#v\n but got: %#v", tt.String, tt.Record.String())
+		expect := tt.Encode
+		if expect == "" {
+			expect = tt.String
+		}
+		if tt.Record.String() != expect {
+			t.Errorf("expected: %#v\n but got: %#v", expect, tt.Record.String())
 		}
 	}
 }