diff --git a/api/portfolio.js b/api/portfolio.js
index 7c79300c..269c9b6a 100644
--- a/api/portfolio.js
+++ b/api/portfolio.js
@@ -1,6 +1,6 @@
 import axios from 'axios';
 import {cacheAdapterEnhancer, Cache} from 'axios-extensions';
-import {differenceInCalendarISOWeeks} from 'date-fns';
+import {differenceInCalendarUTCISOWeeks} from '~/assets/utils/date-fns.js';
 import format from 'date-fns/esm/format';
 import {PORTFOLIO_API_URL, NETWORK, MAINNET} from "~/assets/variables.js";
 import {toSnake} from '~/assets/utils/snake-case.js';
@@ -315,7 +315,7 @@ export function getCmcCoinList() {
 // monday of 43 ISO week
 export const BATTLE_START_DATE = new Date('2022-10-24T00:00:00Z');
 // week number starting from 1
-export const BATTLE_CURRENT_WEEK_NUMBER = differenceInCalendarISOWeeks(new Date(), BATTLE_START_DATE) + 1;
+export const BATTLE_CURRENT_WEEK_NUMBER = differenceInCalendarUTCISOWeeks(new Date(), BATTLE_START_DATE) + 1;
 
 
 /**
diff --git a/assets/utils/date-fns.js b/assets/utils/date-fns.js
new file mode 100644
index 00000000..c900802a
--- /dev/null
+++ b/assets/utils/date-fns.js
@@ -0,0 +1,13 @@
+import getUTCISOWeekSrc from 'date-fns/esm/_lib/getUTCISOWeek/index.js';
+
+const getUTCISOWeek = getUTCISOWeekSrc.default || getUTCISOWeekSrc;
+console.log(getUTCISOWeek);
+/**
+ *
+ * @param {Date|number} dateLeft
+ * @param {Date|number} dateRight
+ * @return {number}
+ */
+export function differenceInCalendarUTCISOWeeks(dateLeft, dateRight) {
+    return getUTCISOWeek(dateLeft) - getUTCISOWeek(dateRight);
+}
diff --git a/jest-babel.config.js b/jest-babel.config.js
new file mode 100644
index 00000000..5ec297a8
--- /dev/null
+++ b/jest-babel.config.js
@@ -0,0 +1,10 @@
+// Custom Jest transform implementation that wraps babel-jest and injects our
+// babel presets, so we don't have to use .babelrc.
+
+import babelJest from 'babel-jest';
+const createTransformer = babelJest.createTransformer || babelJest.default.createTransformer;
+export default createTransformer({
+    babelrc: false,
+    "presets": ["@babel/preset-env"],
+    // ignore: false, // do nothing, jest's transformIgnorePatterns works instead
+});
diff --git a/jest.config.js b/jest.config.js
index 7aba2508..076c0429 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -1,7 +1,13 @@
+const esModules = ['date-fns'].join('|');
+
 export default {
     moduleNameMapper: {
         '~(.*)$': '<rootDir>/$1',
     },
+    transform: {
+        '^.+\\.jsx?$': '<rootDir>/jest-babel.config.js',
+    },
+    transformIgnorePatterns: [`/node_modules/(?!${esModules})`],
     // testEnvironment: 'node',
     // collectCoverage: true,
     // collectCoverageFrom: ["./src/**"],
diff --git a/tests/date-fns.test.js b/tests/date-fns.test.js
new file mode 100644
index 00000000..5a27b6b8
--- /dev/null
+++ b/tests/date-fns.test.js
@@ -0,0 +1,10 @@
+import {differenceInCalendarUTCISOWeeks} from '~/assets/utils/date-fns.js';
+
+test('differenceInCalendarUTCISOWeeks', () => {
+    const BATTLE_START_DATE = new Date('2022-10-24T00:00:00Z');
+    const now = new Date("2022-11-07T01:20:44.498+03:00");
+    expect(differenceInCalendarUTCISOWeeks(new Date("2022-11-07T01:20:44.498+03:00"), BATTLE_START_DATE))
+        .toBe(1);
+    expect(differenceInCalendarUTCISOWeeks(new Date("2022-11-07T01:20:44.498Z"), BATTLE_START_DATE))
+        .toBe(2);
+});