Setup Timezone specification support

package.json

@@ -17,6 +17,7 @@
     "@types/react-dom": "18.0.11",
     "autoprefixer": "^10.4.13",
     "date-fns": "^2.29.3",
+    "date-fns-tz": "^2.0.0",
     "discord.js": "^14.7.1",
     "ioredis": "^5.3.1",
     "life360-node-api": "^0.0.10",

src/env/schema.mjs

@@ -1,6 +1,7 @@
 // @ts-check
 import { z } from 'zod';
 
+const TimezoneSchema = z.enum(Intl.supportedValuesOf("timeZone"));
 /**
  * Specify your server-side environment variables schema here.
  * This way you can ensure the app isn't built with invalid env vars.
@@ -18,5 +19,6 @@ export const serverSchema = z.object({
 	EDGE_CACHE_TIME_SECONDS: z.coerce.number().int().nonnegative().default(60),
 	REDIS_URL: z.string().url(),
 	DISCORD_TOKEN: z.string(),
-	DISCORD_TARGET_USER_ID: z.string()
+	DISCORD_TARGET_USER_ID: z.string(),
+	TIMEZONE: TimezoneSchema
 });

src/env/server.mjs

@@ -19,7 +19,8 @@ const _serverEnv = serverSchema.safeParse({
 	EDGE_CACHE_TIME_SECONDS: process.env.EDGE_CACHE_TIME_SECONDS,
 	REDIS_URL: process.env.REDIS_URL,
 	DISCORD_TOKEN: process.env.DISCORD_TOKEN,
-	DISCORD_TARGET_USER_ID: process.env.DISCORD_TARGET_USER_ID
+	DISCORD_TARGET_USER_ID: process.env.DISCORD_TARGET_USER_ID,
+	TIMEZONE: process.env.TIMEZONE
 });
 
 if (_serverEnv.success === false) {

src/pages/api/health.ts

@@ -5,6 +5,7 @@ import { env } from "@/env/server.mjs";
 type ResponseData = {
   now: number;
   status: string;
+  timezone: string;
 };
 
 export default async function handler(
@@ -14,5 +15,6 @@ export default async function handler(
   res.status(200).json({
     now: new Date().getTime(),
     status: req.query.key == env.API_KEY ? "Authorized" : "Unauthorized",
+    timezone: env.TIMEZONE
   });
 }

src/utils/timezone.ts

@@ -0,0 +1,13 @@
+import { utcToZonedTime } from 'date-fns-tz';
+import { z } from 'zod';
+import { env } from '@/env/server.mjs';
+
+// @ts-ignore TS2339 -- TODO: Figure out why Intl.supportedValuesOf isn't seen by Typescript
+export const TimezoneSchema = z.enum(Intl.supportedValuesOf('timeZone'));
+export type Timezone = z.infer<typeof TimezoneSchema>;
+
+export function localNow(now?: Date, zone?: Timezone): Date {
+	zone = zone ?? env.TIMEZONE;
+	now = now ?? new Date();
+	return utcToZonedTime(now, zone);
+}

tsconfig.json

@@ -1,7 +1,7 @@
 {
 	"compilerOptions": {
 		"target": "ES2016",
-		"lib": ["dom", "dom.iterable", "esnext"],
+		"lib": ["dom", "dom.iterable", "esnext", "es2021.intl"],
 		"allowJs": true,
 		"skipLibCheck": true,
 		"strict": true,

yarn.lock

@@ -357,6 +357,11 @@ csstype@^3.0.2:
   resolved "https://registry.yarnpkg.com/csstype/-/csstype-3.1.1.tgz#841b532c45c758ee546a11d5bd7b7b473c8c30b9"
   integrity sha512-DJR/VvkAvSZW9bTouZue2sSxDwdTN92uHjqeKVm+0dAqdfNykRzQ95tay8aXMBAAPpUiq4Qcug2L7neoRh2Egw==
 
+date-fns-tz@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/date-fns-tz/-/date-fns-tz-2.0.0.tgz#1b14c386cb8bc16fc56fe333d4fc34ae1d1099d5"
+  integrity sha512-OAtcLdB9vxSXTWHdT8b398ARImVwQMyjfYGkKD2zaGpHseG2UPHbHjXELReErZFxWdSLph3c2zOaaTyHfOhERQ==
+
 date-fns@^2.29.3:
   version "2.29.3"
   resolved "https://registry.yarnpkg.com/date-fns/-/date-fns-2.29.3.tgz#27402d2fc67eb442b511b70bbdf98e6411cd68a8"