I spent a few hours trying to figure out how to align the charts datatips to the axis ticks/labels. The solution wasn’t too difficult:

  1. I had to set the axis’s labelUnit/dataUnit as well as the dataInterval to the same value (in my case month)
  2. I had to set the axis’s displayLocalTime property to true, so time zones weren’t used in the chart
  3. (not really relevant) I had to fix a bug in the backend php code that used ‘h’ (us time, am/pm) instead of the correct H (24h time)

Not too complicated but i wasted a lot of time with the axis renderer functions that were the wrong place to look into.