Keep timing and contact state together
Synthetic callback window permits starts 14:00–14:20, excluding 14:20. A starts14:10 unanswered; B starts14:18 and finishes two-way contact14:21; C starts14:20 outside. The preview presents the recorded history, with no calling action.
| Input or inspection | Expected view | Business meaning |
|---|---|---|
| Inspect A | 14:10 · unanswered | Eligible attempt, no contact |
| Inspect B | 14:18 start /14:21 finish | Contact complete; start eligible |
| Inspect C | 14:20 start | Excluded boundary |
Read the event each time describes
- Start and finish use separate columns.
- Unanswered is written explicitly rather than shown as a blank finish.
How many completed contacts started inside the window?
Show the worked answer
One, B. Its 14:21 finish is allowed because the rule controls start.
A recorded attempt supplies no evidence that an update reached the customer.