time zone magic around virtualevent

rowers/courses.py

@@ -16,6 +16,7 @@ import xml.etree.ElementTree as et
 
 import pandas as pd
 import numpy as np
+from timezonefinder import TimezoneFinder
 
 import dataprep
 from rowers.utils import geo_distance
@@ -38,6 +39,24 @@ class InvalidTrajectoryError(Exception):
     def __str__(self):
 	return repr(self.value)
 
+def get_course_timezone(course):
+    polygons = GeoPolygon.objects.filter(course = course)
+    points = GeoPoint.objects.filter(polygon = polygons[0])
+    lat = points[0].latitude
+    lon = points[0].longitude
+
+    tf = TimezoneFinder()
+    try:
+        timezone_str = tf.timezone_at(lng=lon,lat=lat)
+    except ValueError:
+        timezone_str = 'UTC'
+
+    if timezone_str is None:
+        timezone_str = tf.closest_timezone_at(lng=lon,lat=lat)
+        if timezone_str is None:
+            timezone_str = 'UTC'
+
+    return timezone_str
     
 def polygon_to_path(polygon):
     points = GeoPoint.objects.filter(polygon=polygon).order_by("order_in_poly")