Fix parsed date time using a timezone

The `Date` does not include timezone information so the date ISO string
was wrong when run in a different timezone.

package.json

@@ -31,6 +31,7 @@
  "@vueuse/core": "^9.13.0",
  "@vueuse/nuxt": "^9.13.0",
  "csv": "^6.2.7",
+ "date-fns-tz": "^3.1.3",
  "floating-vue": "^2.0.0-beta.20",
  "husky": "^8.0.3",
  "jiti": "^1.18.2",

src/server/api/consume-opening-hours.ts

@@ -1,8 +1,11 @@
+import { fromZonedTime } from 'date-fns-tz';
 import { Client } from '@microsoft/microsoft-graph-client';
 import { ClientSecretCredential } from '@azure/identity';
 import { TokenCredentialAuthenticationProvider } from '@microsoft/microsoft-graph-client/authProviders/azureTokenCredentials/index.js';
 import { serverSupabaseServiceRole } from '#supabase/server';
 
+const timezone = 'Europe/Amsterdam';
+
 const { internalSecret, datoApiToken, microsoftGraph } = useRuntimeConfig();
 
 const credential = new ClientSecretCredential(
@@ -18,7 +21,7 @@ const authProvider = new TokenCredentialAuthenticationProvider(credential, {
 const graphClient = Client.initWithMiddleware({
  authProvider: authProvider,
  fetchOptions: {
- headers: { 'Prefer': 'outlook.timezone="Europe/Amsterdam"' },
+ headers: { 'Prefer': `outlook.timezone="${timezone}"` },
  },
 });
 
@@ -83,15 +86,18 @@ export default defineEventHandler(async (event) => {
  }&$select=subject,start,end`
  )
  .get()
- .then((calendarView) => ({
- number: building.number,
- openEvents: calendarView.value
- .filter((event: CalendarEvent) => event.subject === 'Open')
- .map((event: CalendarEvent) => ({
- start: new Date(event.start.dateTime).toISOString(),
- end: new Date(event.end.dateTime).toISOString(),
- })),
- }))
+ .then((calendarView) => {
+ console.info(`Fetched opening hours of ${buildingsOpeningDates.length} buildings`);
+ return {
+ number: building.number,
+ openEvents: calendarView.value
+ .filter((event: CalendarEvent) => event.subject === 'Open')
+ .map((event: CalendarEvent) => ({
+ start: fromZonedTime(event.start.dateTime, timezone).toISOString(),
+ end: fromZonedTime(event.end.dateTime, timezone).toISOString(),
+ })),
+ }
+ })
  .catch((error) => {
  console.warn(
  `Failed to fetch data for building ${building.number}:`,