Format year of monthly tick lables with 2 digits instead of 4.

Since commit 7b2dfd0 (Oct 15, 2013) the format of monthly tick
labels is `%b %Y` (e.g. Oct 2013). Before the format was '%b %y'
(e.g. Oct 13). Revert to the later format because it seems to be
an accidental change.

  * `dygraph.js`:
    Revert format of monthly tick labels from `%b %Y` to `%b %y`.

diff --git a/dygraph.js b/dygraph.js
index e1b78bd..87a7dab 100644 (file)
--- a/dygraph.js
+++ b/dygraph.js
@@ -233,7 +233,7 @@ Dygraph.dateAxisLabelFormatter = function(date, granularity, opts) {
   if (granularity >= Dygraph.DECADAL) {
     return '' + year;
   } else if (granularity >= Dygraph.MONTHLY) {
-    return Dygraph.SHORT_MONTH_NAMES_[month] + ' ' + year;
+    return Dygraph.SHORT_MONTH_NAMES_[month] + ' ' + Dygraph.zeropad(year % 100);
   } else {
     // 1e-3 factor on millis missing in original implementation
     var frac = hours * 3600 + mins * 60 + secs + 1e-3 * millis;