Original time vs updated time

How can I make those thin lines like on the image? The thin lines are original timestamps, while the “normal” boxes are updated timestamps.

Hi Chris,
in the Gantt you can create such thin lines using addTaskLayer method like in code below:

  renderer: {
    render: function draw_planned(task) {
      if (task.planned_start && task.planned_end) {
        var sizes = gantt.getTaskPosition(task, task.planned_start, task.planned_end);
        var el = document.createElement('div');
        el.className = 'baseline';
        el.style.left = sizes.left + 'px';
        el.style.width = sizes.width + 'px';
        el.style.top = sizes.top + gantt.config.task_height + 13 + 'px';
        return el;
     return false;
// define getRectangle in order to hook layer with the smart rendering
  getRectangle: function(task, view){
      if (task.planned_start && task.planned_end) {
        return gantt.getTaskPosition(task, task.planned_start, task.planned_end);
      return null;

after creating baseline using addTaskLayer and changing CSS:

.baseline {
  position: absolute;
  height: 0;
  opacity: 0.6;
  padding-bottom: 0px;
  background: #049ae1;
  border: 1px solid #049ae1;

the baseline will be as in the image you sent.
I made a snippet close where you can change these lines dynamically via lightbox:
If this is not what you meant, please explain in more detail.