diff --git a/frontend/reply-module/src/__test__/unit/time.test.ts b/frontend/reply-module/src/__test__/unit/time.test.ts
new file mode 100644
index 000000000..cfaaef31d
--- /dev/null
+++ b/frontend/reply-module/src/__test__/unit/time.test.ts
@@ -0,0 +1,37 @@
+// import "@testing-library/jest-dom/extend-expect";
+// import { render } from "@testing-library/react";
+
+import { getTimeDifference } from "../../utils/time";
+
+describe("Time Util", () => {
+  test("getTimeDifference", () => {
+    const beforeThirtySeconds = new Date();
+    beforeThirtySeconds.setSeconds(beforeThirtySeconds.getSeconds() - 1);
+
+    const beforeOneMinute = new Date();
+    beforeOneMinute.setMinutes(beforeOneMinute.getMinutes() - 1);
+
+    const beforeOneHour = new Date();
+    beforeOneHour.setHours(beforeOneHour.getHours() - 1);
+
+    const beforeOneDay = new Date();
+    beforeOneDay.setDate(beforeOneDay.getDate() - 1);
+
+    const beforeOneWeek = new Date();
+    beforeOneWeek.setDate(beforeOneDay.getDate() - 7);
+
+    const beforeOneMonth = new Date();
+    beforeOneMonth.setMonth(beforeOneMonth.getMonth() - 1);
+
+    const beforeOneYear = new Date();
+    beforeOneYear.setFullYear(beforeOneYear.getFullYear() - 1);
+
+    expect(getTimeDifference(beforeThirtySeconds.toString())).toEqual("방금 전");
+    expect(getTimeDifference(beforeOneMinute.toString())).toEqual("1분 전");
+    expect(getTimeDifference(beforeOneHour.toString())).toEqual("1시간 전");
+    expect(getTimeDifference(beforeOneDay.toString())).toEqual("1일 전");
+    expect(getTimeDifference(beforeOneWeek.toString())).toEqual("1주 전");
+    expect(getTimeDifference(beforeOneMonth.toString())).toEqual("1개월 전");
+    expect(getTimeDifference(beforeOneYear.toString())).toEqual("1년 전");
+  });
+});