diff --git a/client.go b/client.go
index 5f61313..0e8454f 100644
--- a/client.go
+++ b/client.go
@@ -17,7 +17,7 @@ func NewClient(opt *RedisOpt) *Client {
 }
 
 // Process enqueues the task to be performed at a given time.
-func (c *Client) Process(task *Task, executeAt time.Time) error {
+func (c *Client) Process(task *Task, processAt time.Time) error {
 	msg := &taskMessage{
 		ID:      uuid.New(),
 		Type:    task.Type,
@@ -25,13 +25,13 @@ func (c *Client) Process(task *Task, executeAt time.Time) error {
 		Queue:   "default",
 		Retry:   defaultMaxRetry,
 	}
-	return c.enqueue(msg, executeAt)
+	return c.enqueue(msg, processAt)
 }
 
 // enqueue pushes a given task to the specified queue.
-func (c *Client) enqueue(msg *taskMessage, executeAt time.Time) error {
-	if time.Now().After(executeAt) {
+func (c *Client) enqueue(msg *taskMessage, processAt time.Time) error {
+	if time.Now().After(processAt) {
 		return c.rdb.enqueue(msg)
 	}
-	return c.rdb.zadd(scheduled, float64(executeAt.Unix()), msg)
+	return c.rdb.schedule(scheduled, processAt, msg)
 }
diff --git a/rdb.go b/rdb.go
index 430e2c0..c84ffd0 100644
--- a/rdb.go
+++ b/rdb.go
@@ -93,16 +93,17 @@ func (r *rdb) lrem(key string, msg *taskMessage) error {
 	return nil
 }
 
-// zadd adds the taskMessage to the specified zset (sorted set) with the given score.
-func (r *rdb) zadd(zset string, zscore float64, msg *taskMessage) error {
+// schedule adds the task to the zset to be processd at the specified time.
+func (r *rdb) schedule(zset string, processAt time.Time, msg *taskMessage) error {
 	bytes, err := json.Marshal(msg)
 	if err != nil {
 		return fmt.Errorf("could not encode task into JSON: %v", err)
 	}
-	err = r.client.ZAdd(zset, &redis.Z{Member: string(bytes), Score: zscore}).Err()
+	score := float64(processAt.Unix())
+	err = r.client.ZAdd(zset, &redis.Z{Member: string(bytes), Score: score}).Err()
 	if err != nil {
 		return fmt.Errorf("command ZADD %s %.1f %s failed: %v",
-			zset, zscore, string(bytes), err)
+			zset, score, string(bytes), err)
 	}
 	return nil
 }
diff --git a/rdb_test.go b/rdb_test.go
index b723851..0ed8af5 100644
--- a/rdb_test.go
+++ b/rdb_test.go
@@ -2,6 +2,7 @@ package asynq
 
 import (
 	"encoding/json"
+	"fmt"
 	"math/rand"
 	"sort"
 	"testing"
@@ -265,3 +266,48 @@ func TestForward(t *testing.T) {
 		}
 	}
 }
+
+func TestSchedule(t *testing.T) {
+	r := setup(t)
+	tests := []struct {
+		msg       *taskMessage
+		processAt time.Time
+		zset      string
+	}{
+		{
+			randomTask("send_email", "default", map[string]interface{}{"subject": "hello"}),
+			time.Now().Add(15 * time.Minute),
+			scheduled,
+		},
+	}
+
+	for _, tc := range tests {
+		// clean up db before each test case.
+		if err := r.client.FlushDB().Err(); err != nil {
+			t.Fatal(err)
+		}
+
+		err := r.schedule(tc.zset, tc.processAt, tc.msg)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+
+		res, err := r.client.ZRangeWithScores(tc.zset, 0, -1).Result()
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+
+		desc := fmt.Sprintf("(*rdb).schedule(%q, %v, %v)", tc.zset, tc.processAt, tc.msg)
+		if len(res) != 1 {
+			t.Errorf("%s inserted %d items to %q, want 1 items inserted", desc, len(res), tc.zset)
+			continue
+		}
+
+		if res[0].Score != float64(tc.processAt.Unix()) {
+			t.Errorf("%s inserted an item with score %f, want %f", desc, res[0].Score, float64(tc.processAt.Unix()))
+			continue
+		}
+	}
+}
diff --git a/retry.go b/retry.go
index 4319b1d..6e93c07 100644
--- a/retry.go
+++ b/retry.go
@@ -20,7 +20,7 @@ func retryTask(rdb *rdb, msg *taskMessage, err error) {
 	fmt.Printf("[DEBUG] Retrying the task in %v\n", retryAt.Sub(time.Now()))
 	msg.Retried++
 	msg.ErrorMsg = err.Error()
-	if err := rdb.zadd(retry, float64(retryAt.Unix()), msg); err != nil {
+	if err := rdb.schedule(retry, retryAt, msg); err != nil {
 		// TODO(hibiken): Not sure how to handle this error
 		log.Printf("[ERROR] could not add msg %+v to 'retry' set: %v\n", msg, err)
 		return