From 498bcc34ebb258e3ded833775b051063f4c52d5c Mon Sep 17 00:00:00 2001
From: Vasyl Nahuliak <vasyl.nahuliak@gmail.com>
Date: Tue, 4 Apr 2023 15:07:16 +0300
Subject: [PATCH] fix: today timezone double shift

---
 src/components/CalendarMonth/CalendarMonth.tsx |  9 +++++++--
 src/date-utils.ts                              | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/components/CalendarMonth/CalendarMonth.tsx b/src/components/CalendarMonth/CalendarMonth.tsx
index 0166a35..a27995d 100644
--- a/src/components/CalendarMonth/CalendarMonth.tsx
+++ b/src/components/CalendarMonth/CalendarMonth.tsx
@@ -3,7 +3,6 @@ import {
   ICalendarEvent,
   isFocusElement,
   typedMemo,
-  utcToZoned,
 } from 'rn-smartsuite-big-calendar';
 
 import { Calendar } from 'react-native-calendars';
@@ -14,6 +13,7 @@ import {
   getDateWithoutTime,
   updateCurrentMonthDay,
   scrollDirection,
+  formatInTimeZone,
 } from '../../date-utils';
 
 import { Container, styles, CalendarContainer } from './styled';
@@ -24,6 +24,7 @@ import type { DateData } from 'react-native-calendars/src/types';
 import { useTheme } from 'styled-components';
 import { CalendarContext } from '../Calendar/CalendarContext';
 import { useSpotlight } from '../../hooks/useSpotlight';
+import TimeInfo from '../../timezone';
 
 function _CalendarMonth<T>({
   ampm,
@@ -160,7 +161,11 @@ function _CalendarMonth<T>({
 
   useEffect(() => focusElementIndex(), [focusEvent?.uniqueId]);
 
-  const formattedToday = getDateWithoutTime(utcToZoned().toISOString());
+  const formattedToday = formatInTimeZone(
+    new Date(),
+    TimeInfo.default().getUserTimezone(),
+    'yyyy-MM-dd'
+  );
 
   return (
     <Container>
diff --git a/src/date-utils.ts b/src/date-utils.ts
index d979841..6e3521f 100644
--- a/src/date-utils.ts
+++ b/src/date-utils.ts
@@ -1,5 +1,6 @@
 import type { DateData } from 'react-native-calendars/src/types';
 import dayjs from 'dayjs';
+import { format, utcToZonedTime } from 'date-fns-tz';
 import { FieldType } from './interfaces';
 import { isAllDayEvent } from './utils';
 
@@ -92,3 +93,17 @@ export const updateCurrentMonthDay = (date: Date) => {
 
 export const scrollDirection = (date: DateData, currentDate?: string) =>
   dayjs.utc(date.dateString).isBefore(currentDate) ? 'RIGHT' : 'LEFT';
+
+// NOTE: date-fns-tz@1.3.7 crash build on android for new users (Invalid date)
+// SOURCE: https://github.com/marnusw/date-fns-tz#formatintimezone
+export const formatInTimeZone = (
+  date: Date | string | number,
+  timeZone: string,
+  formatStr: string
+) => {
+  const extendedOptions = {
+    timeZone,
+  };
+
+  return format(utcToZonedTime(date, timeZone), formatStr, extendedOptions);
+};