replace Sunday with Monday for ISO and Monday-based formats

Author: archmoj

src/plots/cartesian/axes.js

@@ -914,6 +914,13 @@ axes.autoTicks = function(ax, roughDTick) {
             // this will also move the base tick off 2000-01-01 if dtick is
             // 2 or 3 days... but that's a weird enough case that we'll ignore it.
             ax.tick0 = Lib.dateTick0(ax.calendar, true);
+
+            if(/%[uVW]/.test(ax.tickformat)) {
+                // replace Sunday with Monday for ISO and Monday-based formats
+                var len = ax.tick0.length;
+                var lastD = +ax.tick0[len - 1];
+                ax.tick0 = ax.tick0.substring(0, len - 2) + String(lastD + 1);
+            }
         } else if(roughX2 > ONEHOUR) {
             ax.dtick = roundDTick(roughDTick, ONEHOUR, roundBase24);
         } else if(roughX2 > ONEMIN) {