--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/time/week.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,9 @@
+d3.time.week = function(date) {
+  (date = d3.time.day(date)).setDate(date.getDate() - date.getDay());
+  return date;
+};
+
+d3.time.week.utc = function(date) {
+  (date = d3.time.day.utc(date)).setUTCDate(date.getUTCDate() - date.getUTCDay());
+  return date;
+};