improve timezone discovery

backend/src/app/availability_service.py

@@ -70,7 +70,7 @@ async def calculate_availability(
     participants = {p.id: p for p in participants_result.scalars().all()}
 
     days = ["Mon", "Tue", "Wed", "Thu", "Fri"]
-    hours = list(range(9, 18))
+    hours = list(range(0, 24))
     slots = []
 
     for day_offset, day_name in enumerate(days):
@@ -98,6 +98,7 @@ async def calculate_availability(
             slots.append({
                 "day": slot_start.strftime("%Y-%m-%d"),
                 "hour": hour,
+                "start_time": slot_start,
                 "availability": availability,
                 "availableParticipants": available_participants,
             })

backend/src/app/main.py

@@ -15,6 +15,7 @@ from app.schemas import (
     AvailabilityRequest,
     AvailabilityResponse,
     ParticipantCreate,
+    ParticipantUpdate,
     ParticipantResponse,
     SyncResponse,
     ScheduleRequest,
@@ -63,6 +64,7 @@ async def create_participant(
     participant = Participant(
         name=data.name,
         email=data.email,
+        timezone=data.timezone,
         ics_url=data.ics_url,
     )
     db.add(participant)
@@ -95,6 +97,35 @@ async def get_participant(participant_id: UUID, db: AsyncSession = Depends(get_d
     return participant
 
 
+@app.patch("/api/participants/{participant_id}", response_model=ParticipantResponse)
+async def update_participant(
+    participant_id: UUID, data: ParticipantUpdate, db: AsyncSession = Depends(get_db)
+):
+    result = await db.execute(
+        select(Participant).where(Participant.id == participant_id)
+    )
+    participant = result.scalar_one_or_none()
+    if not participant:
+        raise HTTPException(status_code=404, detail="Participant not found")
+
+    if data.timezone is not None:
+        participant.timezone = data.timezone
+    if data.ics_url is not None:
+        participant.ics_url = data.ics_url if data.ics_url else None
+
+    await db.commit()
+    await db.refresh(participant)
+
+    # Re-sync calendar if ICS URL was updated
+    if data.ics_url is not None and participant.ics_url:
+        try:
+            await sync_participant_calendar(db, participant)
+        except Exception as e:
+            logger.warning(f"Calendar sync failed for {participant.email}: {e}")
+
+    return participant
+
+
 @app.delete("/api/participants/{participant_id}")
 async def delete_participant(participant_id: UUID, db: AsyncSession = Depends(get_db)):
     result = await db.execute(

backend/src/app/models.py

@@ -18,6 +18,7 @@ class Participant(Base):
     )
     name: Mapped[str] = mapped_column(String(255), nullable=False)
     email: Mapped[str] = mapped_column(String(255), nullable=False, unique=True)
+    timezone: Mapped[str] = mapped_column(String(50), nullable=False, default="America/Toronto")
     ics_url: Mapped[str | None] = mapped_column(Text, nullable=True)
     created_at: Mapped[datetime] = mapped_column(
         DateTime, default=datetime.utcnow, nullable=False

backend/src/app/schemas.py

@@ -7,6 +7,12 @@ from pydantic import BaseModel, EmailStr
 class ParticipantCreate(BaseModel):
     name: str
     email: EmailStr
+    timezone: str = "America/Toronto"
+    ics_url: str | None = None
+
+
+class ParticipantUpdate(BaseModel):
+    timezone: str | None = None
     ics_url: str | None = None
 
 
@@ -14,6 +20,7 @@ class ParticipantResponse(BaseModel):
     id: UUID
     name: str
     email: str
+    timezone: str
     ics_url: str | None
     created_at: datetime
     updated_at: datetime
@@ -25,6 +32,7 @@ class ParticipantResponse(BaseModel):
 class TimeSlot(BaseModel):
     day: str
     hour: int
+    start_time: datetime
     availability: str
     availableParticipants: list[str]