Upload utils.py

api/utils.py

@@ -1,4 +1,4 @@
-from datetime import datetime, date, time, timedelta
+from datetime import datetime, time, timedelta
 
 def hms_to_seconds(hms_str):
     """Converts GTFS 'HH:MM:SS' (e.g. '25:30:00') to total seconds from midnight."""
@@ -7,19 +7,50 @@ def hms_to_seconds(hms_str):
 
 def get_service_day_start_ts():
     """
-    Returns the Unix timestamp for 00:00:00 of the CURRENT service day.
-    TTC service day typically flips at 4:00 AM.
+    Returns the Unix timestamp (UTC) for 00:00:00 of the CURRENT service day.
+    TTC service day flips at 4:00 AM Eastern time (handles DST automatically).
+    All timestamps are in UTC to match GTFS Realtime timestamps.
     """
-    now = datetime.now()
-    # If it's 2 AM, we are still technically on 'yesterday's' schedule
-    if now.hour < 4:
-        service_date = date.today() - timedelta(days=1)
+    from datetime import timezone
+    try:
+        # Python 3.9+ has zoneinfo built-in
+        from zoneinfo import ZoneInfo
+        eastern_tz = ZoneInfo("America/Toronto")
+    except ImportError:
+        # Fallback for older Python versions - use pytz if available
+        try:
+            import pytz
+            eastern_tz = pytz.timezone("America/Toronto")
+        except ImportError:
+            # Last resort: hardcoded UTC-5 (EST), no DST handling
+            now_utc = datetime.now(timezone.utc)
+            if now_utc.hour < 9:  # 4 AM Eastern = 9 AM UTC (EST)
+                service_date = now_utc.date() - timedelta(days=1)
+            else:
+                service_date = now_utc.date()
+            service_start_utc = datetime.combine(service_date, time.min, tzinfo=timezone.utc) + timedelta(hours=5)
+            return int(service_start_utc.timestamp())
+    
+    # Get current UTC time and convert to Eastern
+    now_utc = datetime.now(timezone.utc)
+    now_eastern = now_utc.astimezone(eastern_tz)
+    
+    # TTC service day flips at 4:00 AM Eastern
+    if now_eastern.hour < 4:
+        service_date = now_eastern.date() - timedelta(days=1)
     else:
-        service_date = date.today()
+        service_date = now_eastern.date()
+    
+    # Create datetime at 00:00:00 Eastern, convert to UTC
+    try:
+        # zoneinfo (Python 3.9+)
+        service_start_eastern = datetime.combine(service_date, time.min, tzinfo=eastern_tz)
+    except TypeError:
+        # pytz needs localize
+        service_start_eastern = eastern_tz.localize(datetime.combine(service_date, time.min))
     
-    # Combine that date with 00:00:00 and get the timestamp
-    service_start_dt = datetime.combine(service_date, time.min)
-    return int(service_start_dt.timestamp())
+    service_start_utc = service_start_eastern.astimezone(timezone.utc)
+    return int(service_start_utc.timestamp())
 
 def translate_occupancy(status):
     """Maps GTFS occupancy enums to human readable strings."""