diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index 489be2ac..42c17c76 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -758,7 +758,7 @@ def getpartofday(row,r):
         tf = TimezoneFinder()
         try:
             timezone_str = tf.timezone_at(lng=lonavg, lat=latavg)
-        except ValueError:
+        except (ValueError,OverflowError):
             timezone_str = 'UTC'
         if timezone_str == None:
             timezone_str = tf.closest_timezone_at(lng=lonavg,