With our 'Classic' (standard) scheduling system, you can give contractors the ability to 'Request sign-off on tasks' (via the project or branches schedule settings page). This means that when the contractor has completed their task, they can let the PM or Site Manager know (via RAVE) that their assigned task has been finished - allowing the PM or Site Manager to check and confirm the work is up to standard before it has been marked off as complete.
With RAVE's optional Enterprise scheduling module, you have the ability to let your contractors Accept or Decline a task (i.e. are they available to do the task on the dates you've set) and also the option to Propose a New Start Date - letting you know what dates they can do if they can't do your selected dates.
When this feature is enabled the task Acceptance, Decline, or Propose a new start date is displayed on both the Task List and Task Gantt views - as a tick, cross or triangle alert respectively.
This feature is useful once you have put together your schedule, with timelines sorted, tasks assigned to contractors, the project is active, and the schedule activated - so your contractors can see it.