From 05133a78ac9d389bf3e2f48b8a2db587e14f048a Mon Sep 17 00:00:00 2001
From: john gravois <jagravois@gmail.com>
Date: Sat, 9 Nov 2024 12:57:26 -0800
Subject: [PATCH] account for daylight savings time (#34)

* very wip

* account for daylight savings time

* less is more
---
 app/routes/reservations.new.tsx |  5 +++--
 app/utils.ts                    | 12 +++++++++---
 package-lock.json               | 14 ++++++++++----
 package.json                    |  4 ++--
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/app/routes/reservations.new.tsx b/app/routes/reservations.new.tsx
index 75a8bd9..a99e1c1 100644
--- a/app/routes/reservations.new.tsx
+++ b/app/routes/reservations.new.tsx
@@ -13,7 +13,7 @@ import {
   requireValidStytchToken,
   sessionStorage,
 } from "~/session.server";
-import { anotherTimeFormattingFunc } from "~/utils";
+import { anotherTimeFormattingFunc, getPacificOffset } from "~/utils";
 
 // if an anonymous or stale user gets here, fail fast
 export const loader = async ({ request }: LoaderFunctionArgs) => {
@@ -65,7 +65,8 @@ export const action = async ({ request }: ActionFunctionArgs) => {
     return json({ errors: { start: "court is required" } }, { status: 400 });
   }
 
-  const start = new Date(`${startDate}T${startTime}:00-07:00`);
+  const offset = getPacificOffset(startDate);
+  const start = new Date(`${startDate}T${startTime}:00-0${offset}:00`);
 
   try {
     await createReservation({
diff --git a/app/utils.ts b/app/utils.ts
index 7cfbe86..53af0d7 100644
--- a/app/utils.ts
+++ b/app/utils.ts
@@ -1,7 +1,7 @@
+import { tz, TZDate } from "@date-fns/tz";
 import { useMatches } from "@remix-run/react";
 import { contains } from "@terraformer/spatial";
-import { addDays } from "date-fns";
-import { formatInTimeZone } from "date-fns-tz";
+import { addDays, format as dateFnsFormat } from "date-fns";
 import type { GeoJSON } from "geojson";
 import { useMemo } from "react";
 
@@ -32,6 +32,12 @@ export const anotherTimeFormattingFunc = (val: string | null) => {
   return formatTime(Number(h), m == "30");
 };
 
+// either GMT -7 or -8 depending on the season
+export const getPacificOffset = (rawDate: string) => {
+  const [year, month, day] = rawDate.split("-").map((val) => Number(val));
+  return new TZDate(year, month, day, "America/Los_Angeles").getTimezoneOffset() / 60;
+}
+
 export const getTimezoneOffsetMs = (date: Date) => {
   const invdate = new Date(
     date.toLocaleString("en-US", {
@@ -49,7 +55,7 @@ export const getTimezoneOffset = (date: Date) => {
 }
 
 export const format = (date: Date | string, format: string) =>
-  formatInTimeZone(date, "America/Los_Angeles", format);
+  dateFnsFormat(date, format, { in: tz("America/Los_Angeles") });
 
 export const formatTime = (rawHour: number, isHalf = false): string => {
   const hour = rawHour - (rawHour > 12 ? 12 : 0)
diff --git a/package-lock.json b/package-lock.json
index 8dd23aa..28aaca6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6,6 +6,7 @@
     "": {
       "name": "court-dibs",
       "dependencies": {
+        "@date-fns/tz": "^1.2.0",
         "@googlemaps/js-api-loader": "^1.16.6",
         "@prisma/client": "^4.16.2",
         "@remix-run/css-bundle": "^2.8.0",
@@ -14,7 +15,7 @@
         "@remix-run/serve": "^2.8.0",
         "@terraformer/spatial": "^2.1.2",
         "classnames": "^2.5.1",
-        "date-fns": "^3.4.0",
+        "date-fns": "^4.1.0",
         "date-fns-tz": "^3.1.3",
         "isbot": "^3.7.0",
         "react": "^18.2.0",
@@ -912,6 +913,11 @@
         "ms": "^2.1.1"
       }
     },
+    "node_modules/@date-fns/tz": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@date-fns/tz/-/tz-1.2.0.tgz",
+      "integrity": "sha512-LBrd7MiJZ9McsOgxqWX7AaxrDjcFVjWH/tIKJd7pnR7McaslGYOP1QmmiBXdJH/H/yLCT+rcQ7FaPBUxRGUtrg=="
+    },
     "node_modules/@emotion/hash": {
       "version": "0.9.1",
       "resolved": "https://registry.npmjs.org/@emotion/hash/-/hash-0.9.1.tgz",
@@ -5828,9 +5834,9 @@
       }
     },
     "node_modules/date-fns": {
-      "version": "3.4.0",
-      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-3.4.0.tgz",
-      "integrity": "sha512-Akz4R8J9MXBsOgF1QeWeCsbv6pntT5KCPjU0Q9prBxVmWJYPLhwAIsNg3b0QAdr0ttiozYLD3L/af7Ra0jqYXw==",
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-4.1.0.tgz",
+      "integrity": "sha512-Ukq0owbQXxa/U3EGtsdVBkR1w7KOQ5gIBqdH2hkvknzZPYvBxb/aa6E8L7tmjFtkwZBu3UXBbjIgPo/Ez4xaNg==",
       "funding": {
         "type": "github",
         "url": "https://github.com/sponsors/kossnocorp"
diff --git a/package.json b/package.json
index fb4b0ad..641ca99 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,7 @@
     "/public/build"
   ],
   "dependencies": {
+    "@date-fns/tz": "^1.2.0",
     "@googlemaps/js-api-loader": "^1.16.6",
     "@prisma/client": "^4.16.2",
     "@remix-run/css-bundle": "^2.8.0",
@@ -33,8 +34,7 @@
     "@remix-run/serve": "^2.8.0",
     "@terraformer/spatial": "^2.1.2",
     "classnames": "^2.5.1",
-    "date-fns": "^3.4.0",
-    "date-fns-tz": "^3.1.3",
+    "date-fns": "^4.1.0",
     "isbot": "^3.7.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",