diff --git a/src/lib/constants.ts b/src/lib/constants.ts
index 888c1484..a548826a 100644
--- a/src/lib/constants.ts
+++ b/src/lib/constants.ts
@@ -30,6 +30,8 @@ export const FILTER_RANGE = 'filter-range';
 export const FILTER_REFERRERS = 'filter-referrers';
 export const FILTER_PAGES = 'filter-pages';
 
+export const UNIT_TYPES = ['year', 'month', 'hour', 'day'];
+
 export const USER_FILTER_TYPES = {
   all: 'All',
   username: 'Username',
diff --git a/src/lib/yup.ts b/src/lib/yup.ts
index 8b2eceee..a2ea46d8 100644
--- a/src/lib/yup.ts
+++ b/src/lib/yup.ts
@@ -1,5 +1,6 @@
 import moment from 'moment';
 import * as yup from 'yup';
+import { UNIT_TYPES } from './constants';
 
 export const DateRangeValidation = {
   startAt: yup.number().integer().required(),
@@ -20,5 +21,11 @@ export function getFilterValidation(matchRegex) {
 export const TimezoneTest = yup.string().test(
   'timezone',
   () => `Invalid timezone`,
-  value => !moment.tz.zone(value),
+  value => !value || !moment.tz.zone(value),
+);
+
+export const UnitTypeTest = yup.string().test(
+  'unit',
+  () => `Invalid unit`,
+  value => !value || !UNIT_TYPES.includes(value),
 );
diff --git a/src/pages/api/websites/[id]/events.ts b/src/pages/api/websites/[id]/events.ts
index 422200f8..32288aa5 100644
--- a/src/pages/api/websites/[id]/events.ts
+++ b/src/pages/api/websites/[id]/events.ts
@@ -1,22 +1,19 @@
-import { WebsiteMetric, NextApiRequestQueryBody } from 'lib/types';
 import { canViewWebsite } from 'lib/auth';
 import { useAuth, useCors, useValidate } from 'lib/middleware';
-import moment from 'moment-timezone';
-import { NextApiResponse } from 'next';
-import { badRequest, methodNotAllowed, ok, unauthorized } from 'next-basics';
-import { getEventMetrics } from 'queries';
 import { parseDateRangeQuery } from 'lib/query';
+import { NextApiRequestQueryBody, WebsiteMetric } from 'lib/types';
+import { TimezoneTest, UnitTypeTest } from 'lib/yup';
+import { NextApiResponse } from 'next';
+import { methodNotAllowed, ok, unauthorized } from 'next-basics';
+import { getEventMetrics } from 'queries';
 import * as yup from 'yup';
-import { TimezoneTest } from 'lib/yup';
-
-const unitTypes = ['year', 'month', 'hour', 'day'];
 
 export interface WebsiteEventsRequestQuery {
   id: string;
   startAt: string;
   endAt: string;
-  unit: string;
-  timezone: string;
+  unit?: string;
+  timezone?: string;
   url: string;
 }
 
@@ -25,8 +22,8 @@ const schema = {
     id: yup.string().uuid().required(),
     startAt: yup.number().integer().required(),
     endAt: yup.number().integer().moreThan(yup.ref('startAt')).required(),
-    unit: yup.string().required(),
-    timezone: TimezoneTest.required(),
+    unit: UnitTypeTest,
+    timezone: TimezoneTest,
     url: yup.string(),
   }),
 };
@@ -49,10 +46,6 @@ export default async (
       return unauthorized(res);
     }
 
-    if (!moment.tz.zone(timezone) || !unitTypes.includes(unit)) {
-      return badRequest(res);
-    }
-
     const events = await getEventMetrics(websiteId, {
       startDate,
       endDate,
diff --git a/src/pages/api/websites/[id]/pageviews.ts b/src/pages/api/websites/[id]/pageviews.ts
index 8c10ffeb..0f034cc2 100644
--- a/src/pages/api/websites/[id]/pageviews.ts
+++ b/src/pages/api/websites/[id]/pageviews.ts
@@ -23,14 +23,14 @@ export interface WebsitePageviewRequestQuery {
   city?: string;
 }
 
-import { TimezoneTest } from 'lib/yup';
+import { TimezoneTest, UnitTypeTest } from 'lib/yup';
 import * as yup from 'yup';
 const schema = {
   GET: yup.object().shape({
     id: yup.string().uuid().required(),
     startAt: yup.number().required(),
     endAt: yup.number().required(),
-    unit: yup.string(),
+    unit: UnitTypeTest,
     timezone: TimezoneTest,
     url: yup.string(),
     referrer: yup.string(),