1. **Problem statement:** You usually work from 8:00 to 15:00, which is 7 hours. 2. You arrived late at 8:30 and plan to leave at 15:30, so your total worked time without permission leave is from 8:30 to 15:30. 3. Calculate the total worked time without permission leave: $$15:30 - 8:30 = 7 \text{ hours}$$ 4. You want to request a permission leave for 30 minutes (0.5 hours). 5. To compensate for the 30 minutes permission leave, you need to add this time to your leaving time. 6. Since you plan to leave at 15:30, subtract the permission leave time to find the timestamp of the permission request: $$15:30 - 0:30 = 15:00$$ 7. **Answer:** The timestamp of the permission request is at 15:00. This means you are requesting permission to leave 30 minutes earlier than your planned leaving time of 15:30.