diff --git a/src/util.js b/src/util.js
index b710945..4ff0334 100644
--- a/src/util.js
+++ b/src/util.js
@@ -92,4 +92,27 @@ export class Util {
         return result;
     }
 
+    /*＊
+     * format the time string to int
+     *
+     * @param {time}
+     * @type {Date} 
+     * @desc the time need to be format
+     *
+     * @param {interval}
+     * @type {Int} 
+     * @desc interval means the one-time password's life,
+     * default to be 30.
+     *
+     * @return {Int}
+     */
+    static timecode(time, interval) {
+        let time_str = Date.parse(time).toString();
+
+        // fotmat the time, the ms is not needed.
+        let format_time = time_str.substring(0, time_str.length-3);
+
+        return parseInt(parseInt(format_time) / interval);
+    }
+
 }
\ No newline at end of file
diff --git a/test/util_test.js b/test/util_test.js
index 78b487c..cfb6435 100644
--- a/test/util_test.js
+++ b/test/util_test.js
@@ -31,6 +31,13 @@ describe('Util module test', function() {
             let input = 49957590;
             assert.equal("\u0000\u0000\u0000\u0000\u0002úJÖ", a.int_to_bytestring(input));
         });
-    });    
+    });
+
+    describe('static timecode() function', function() {
+        it("should format the time string to int", function() {
+            let now = new Date();
+            assert.equal("number", typeof(a.timecode(now, 30)));
+        });
+    });  
 
 });