added basic support for Date (if Y and or X data is a Date .getTime() is automatically called)

however to detect the need of a conversion only the first entry in the data array is checked
and the conversion is not really efficient.

curvedLines.js

@@ -37,7 +37,6 @@
 
  This is version 0.1 of curvedLines so it will probably not work in every case. However
  the basic form of use descirbed next works (:
-
  Feel free to further improve the code
 
  ____________________________________________________
@@ -50,7 +49,6 @@
  var options = { series: { curvedLines: { active: true }}};
 
  $.plot($("#placeholder"), [{data = d1, curvedLines: { show: true}}], options);
-
  _____________________________________________________
 
  options:
@@ -67,7 +65,6 @@
  fitPointDist:	   int  	defines the x axis distance of the additional two points that are used
                         	to enforce the min max condition. (you will get curvePointFactor * 3 * |datapoints|
                         	"virtual" points if fit is true)
-
  */
 
 /*
@@ -131,14 +128,45 @@
 						ctx.fillStyle = c.toString();
 					}
 					ctx.lineWidth = series.curvedLines.lineWidth;
+					var points, dataX, dataY, data;
+
+					//convenience check for x or y values if they are Dates if so apply .getTime()
+					//only check on first value mixing numeric and Date fields in one input array is not allowed
+					if (series.data[0][0] instanceof Date || series.data[0][1] instanceof Date) {
+						data = series.data.map(getTimeFromDate);
+					} else {
+						//default case
+						data = series.data;
+					}
 
-					var points = calculateCurvePoints(series.data, series.curvedLines);
+					var points = calculateCurvePoints(data, series.curvedLines);
 					plotLine(ctx, points, axisx, axisy, series.curvedLines.fill);
 					ctx.restore();
 				}
 			}
 		}
 
+		//helper method that convertes Dates to a numeric representation
+		function getTimeFromDate(timeElement) {
+			var xVal = timeElement[0];
+			var yVal = timeElement[1];
+			var ret = new Array;
+
+			if (timeElement[0] instanceof Date) {
+				ret[0] = xVal.getTime();
+			} else {
+				ret[0] = xVal;
+			}
+
+			if (timeElement[1] instanceof Date) {
+				ret[1] = yVal.getTime();
+			} else {
+				ret[1] = yVal;
+			}
+
+			return ret;
+		}
+
 		//nearly the same as in the core library
 		//only ps is adjusted to 2
 		function plotLine(ctx, points, axisx, axisy, fill) {
@@ -231,7 +259,7 @@
 		}
 
 		//no real idea whats going on here code mainly from https://code.google.com/p/flot/issues/detail?id=226
-		//I don't understand what nergal computes here and to be honest I didn't even try
+		//if fit option is selected additional datapoints get inserted before the curve calculations in nergal.dev s code.
 		function calculateCurvePoints(data, curvedLinesOptions) {
 
 			var num = curvedLinesOptions.curvePointFactor * data.length;
@@ -358,4 +386,3 @@
 	});
 
 })(jQuery);
-