- var format = '%d%b'; // e.g. "1 Jan"
- // TODO(danvk): be smarter about making sure this really hits a "nice" time.
- if (granularity < Dygraph.HOURLY) {
- start_time = spacing * Math.floor(0.5 + start_time / spacing);
+ var format = '%d%b'; // e.g. "1Jan"
+
+ // Find a time less than start_time which occurs on a "nice" time boundary
+ // for this granularity.
+ var g = spacing / 1000;
+ var d = new Date(start_time);
+ if (g <= 60) { // seconds
+ var x = d.getSeconds(); d.setSeconds(x - x % g);
+ } else {
+ d.setSeconds(0);
+ g /= 60;
+ if (g <= 60) { // minutes
+ var x = d.getMinutes(); d.setMinutes(x - x % g);
+ } else {
+ d.setMinutes(0);
+ g /= 60;
+
+ if (g <= 24) { // days
+ var x = d.getHours(); d.setHours(x - x % g);
+ } else {
+ d.setHours(0);
+ g /= 24;
+
+ if (g == 7) { // one week
+ d.setDate(d.getDate() - d.getDay());
+ }
+ }
+ }