--- a/trafficintelligence/utils.py	Tue Jul 10 17:16:38 2018 -0400
+++ b/trafficintelligence/utils.py	Wed Jul 11 01:48:42 2018 -0400
@@ -342,6 +342,10 @@
 def timeToFrames(t, frameRate):
     return frameRate*(t.hour*3600+t.minute*60+t.second)
 
+def timeModulo(t, duration):
+    'returns the time modulo the duration in min'
+    return time(t.hour, t.minute//duration, t.second)
+
 def sortXY(X,Y):
     'returns the sorted (x, Y(x)) sorted on X'
     D = {}