Here's a guide on how you should reschedule your Tasks when you deviate from what was scheduled.
No work was done
Delete the Task Event (Refer to Modifying Task Events).
Reclaim will reschedule it within in a few seconds at some point in the near future.
Some work was done
Adjust the duration of the Task Event (Refer to Modifying Task Events).
Reclaim will realize you still need the remaining amount of time for work and will schedule that on the calendar.
Work was done in the scheduled time, but more time is needed to complete the Task
Use the Add time feature to add time (Refer to Add time to your Task Policy).
Time will be added to the overall Task Policy and Reclaim will schedule time in the future to complete the Task.