1 d3.time.month = function(date) {

     2   return new Date(date.getFullYear(), date.getMonth(), 1);

     3 };

     4 

     5 d3.time.month.utc = function(date) {

     6   return new Date(Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), 1));

     7 };