The building company you are contracting to have the option to to let you Accept or Decline a task (i.e. are you available to do the task on the dates they've set) and also the option to Propose a New Start Date - letting them know what dates you can do if you can't do their selected dates.
Let's have a look at the 'Accept or Decline Tasks' workflow from the contractors view.
Accepting/Declining Tasks - Contractor Log-in View
Firstly, logging in as a Contractor, opening this particular project, and clicking on the ‘Schedule’ sub-tab, we can see they have three tasks assigned him - let's test out the different workflows.
Accepting a Task - Contractor Log-in View
Click the green ‘Accept’ button to confirm.
This will open the contractors 'Accept Task Assignment' pop-up
The contractor has the ability to type in a message, and click 'Confirm’ to accept the task, locking in their acceptance to do that task on the dates required. 
After you accept the task, youwill see a blue ‘Request Sign Off’ button appear. When the task is completed, click the ‘Request Sign Off’ button to notify the project manager that this task has been done - ready for the PM or Site Manager to confirm the task has been completed to their level of standard.
Declining a Task + Propose a New Start Date - Contractor Log-in View
If you can NOT do the task on the days requested, click the red ‘Decline’ button to advise this.
This will open the 'Decline Task Assignment' pop-up
Again, you have the ability to type in a message, and the option of 'Proposing a New Start Date'. If the 'Propose a New Start Date' option is selected, a calendar drop-down will appear, for you to select the dates that you can do the task, and the ‘Confirm’ button to request this reschedule of the tasks.
After you 'Decline' and 'Proposes a New Start Date' on that task, you will see a ‘Reschedule Requested’ tag appear in blue text - the PM is notified, and the ball is now back in the PM's court to decide whether they want to accept when the task can be completed.
- If the PM accepts the change - the new dates will be locked in, and the blue 'Request Sign Off' button will appear for you.
- If the PM declines the change, and assigns the task to someone else instead, the task will disappear from your view.
