There is no way to recognize that a schedule has slipped in Aha. It would be beneficial to allow saving of a baseline once a schedule Gantt has been built so you can recognize slips just by looking at the Gantt.
Baseline should collect start/end dates for the schedule and all sub-items. (Phases, Features, Epics, etc.)
You should be able to view the baseline and actuals on the same chart so you can compare and easily see changed dates.
Bonus if you can save multiple baselines.