uxdy: Fix month being off by 1 in the date selector button

Author: SheepTester

classrooms/components/date-time/DateTimeButton.tsx

@@ -36,9 +36,7 @@ export function DateTimeButton ({
       <p class='showing-schedule-wrapper'>
         <span class='showing-schedule-text'>Showing schedule for</span>
         <div class='date-time'>
-          {dateFormat.format(
-            new Date(date.year, date.month, date.date, time.hour, time.minute)
-          )}
+          {dateFormat.format(date.toLocal(time.hour, time.minute))}
         </div>
         {current && (
           <span class='quarter-week'>

util/Day.ts

@@ -23,6 +23,7 @@ export class Day {
     return this.#date.getUTCFullYear()
   }
 
+  /** 1-indexed. */
   get month (): number {
     return this.#date.getUTCMonth() + 1
   }
@@ -115,10 +116,11 @@ export class Day {
   }
 
   /**
-   * Converts the Date to the date in local time at the start of the day.
+   * Converts the Date to the date in local time. If time is not specified, it
+   * defaults to midnight at the start of the day.
    */
-  toLocal (): Date {
-    return new Date(this.year, this.month - 1, this.date)
+  toLocal (hour = 0, minute = 0): Date {
+    return new Date(this.year, this.month - 1, this.date, hour, minute)
   }
 
   /**