improve timezone discovery

frontend/src/components/AvailabilityHeatmap.tsx

@@ -7,7 +7,8 @@ import {
 } from '@/components/ui/popover';
 import { Button } from '@/components/ui/button';
 import { Check, X, Loader2 } from 'lucide-react';
-import { TimezoneSelector } from '@/components/TimezoneSelector';
+
+const TIMEZONE = 'America/Toronto';
 
 const dayNames = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri'];
 const hours = [9, 10, 11, 12, 13, 14, 15, 16, 17];
@@ -78,8 +79,6 @@ interface AvailabilityHeatmapProps {
   onSlotSelect: (slot: TimeSlot) => void;
   showPartialAvailability?: boolean;
   isLoading?: boolean;
-  displayTimezone: string;
-  onTimezoneChange: (timezone: string) => void;
 }
 
 export const AvailabilityHeatmap = ({
@@ -88,15 +87,13 @@ export const AvailabilityHeatmap = ({
   onSlotSelect,
   showPartialAvailability = false,
   isLoading = false,
-  displayTimezone,
-  onTimezoneChange,
 }: AvailabilityHeatmapProps) => {
-  const weekDates = getWeekDates(displayTimezone);
+  const weekDates = getWeekDates(TIMEZONE);
 
   // Find a slot that matches the given display timezone date/hour
   const getSlot = (dateStr: string, hour: number): TimeSlot | undefined => {
     // Convert display timezone date/hour to UTC
-    const targetUTC = toUTCDate(dateStr, hour, displayTimezone);
+    const targetUTC = toUTCDate(dateStr, hour, TIMEZONE);
 
     return slots.find((s) => {
       const slotDate = new Date(s.start_time);
@@ -118,7 +115,7 @@ export const AvailabilityHeatmap = ({
 
   const isSlotTooSoon = (dateStr: string, hour: number) => {
     // Convert to UTC and compare with current time
-    const slotTimeUTC = toUTCDate(dateStr, hour, displayTimezone);
+    const slotTimeUTC = toUTCDate(dateStr, hour, TIMEZONE);
     const now = new Date();
     const twoHoursFromNow = new Date(now.getTime() + 2 * 60 * 60 * 1000);
     return slotTimeUTC < twoHoursFromNow;
@@ -177,10 +174,6 @@ export const AvailabilityHeatmap = ({
             {selectedParticipants.length} participant{selectedParticipants.length > 1 ? 's' : ''}: {selectedParticipants.map(p => p.name.split(' ')[0]).join(', ')}
           </p>
         </div>
-        <TimezoneSelector
-          value={displayTimezone}
-          onChange={onTimezoneChange}
-        />
       </div>
 
       <div className="overflow-x-auto">
@@ -242,19 +235,6 @@ export const AvailabilityHeatmap = ({
                             {selectedParticipants.map((participant) => {
                               const isAvailable = slot.availableParticipants.includes(participant.name);
 
-                              // Calculate participant's local time for this slot
-                              let participantTime = '';
-                              try {
-                                const slotDate = new Date(slot.start_time);
-                                participantTime = new Intl.DateTimeFormat('en-US', {
-                                  hour: 'numeric',
-                                  minute: 'numeric',
-                                  timeZone: participant.timezone,
-                                }).format(slotDate);
-                              } catch (e) {
-                                // Fallback if timezone is invalid
-                              }
-
                               return (
                                 <div
                                   key={participant.id}
@@ -269,9 +249,6 @@ export const AvailabilityHeatmap = ({
                                     isAvailable ? "text-foreground" : "text-muted-foreground"
                                   )}>
                                     {participant.name.split(' ')[0]}
-                                    <span className="opacity-70 ml-1">
-                                      ({participantTime || '?'})
-                                    </span>
                                   </span>
                                 </div>
                               );