Timeline comparisons: How to visualize schedule slippage?

Let’s say I have a set of “task” entities that comprises a Project; each task has:

  • a scheduled start and end date; and
  • an actual start and end date.

Thus there are two timelines: one for the scheduled task dates and another for the actual task dates.

Is there a way to combine/compare these two timelines in a single view, to be able to judge schedule slippage visually?