account for daylight savings in dusk calculations

jgravois · Jan 3, 2025 · 0f31066 · 0f31066
1 parent 05133a7
commit 0f31066
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/app/components/DuskCalculator.tsx b/app/components/DuskCalculator.tsx
@@ -1,6 +1,8 @@
 import { addMinutes } from "date-fns";
 import * as SunCalc from "suncalc";
 
+import { getPacificOffset } from "~/utils";
+
 const LAT_LONG = [-117.7, 33.5].reverse() as [number, number];
 
 // determine whether a America/Los_Angeles reservation
@@ -15,7 +17,8 @@ export const DuskCalculator = ({
   duration: string;
   startTime: string;
 }) => {
-  const start = new Date(`${date}T${startTime}:00-07:00`);
+  const offset = getPacificOffset(date);
+  const start = new Date(`${date}T${startTime}:00-0${offset}:00`);
   const end = addMinutes(start, Number(duration));
   const { dusk } = SunCalc.getTimes(start, ...LAT_LONG);
 

diff --git a/app/utils.ts b/app/utils.ts
@@ -32,7 +32,7 @@ export const anotherTimeFormattingFunc = (val: string | null) => {
   return formatTime(Number(h), m == "30");
 };
 
-// either GMT -7 or -8 depending on the season
+// 7 or 8 (from GMT) 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;