As a result, I had a series of micro-lie-ins this morning, in the knowledge of the approximate time, and eventually got out of bed at sometime after 9. About 10 past. I got dressed, went downstairs, filled a bucket with water to allow me to flush the toilet, brushed my teeth reviewing the previous evening's plastering efforts, generally got myself psyched up to leave the house, and arrived in my car at 9.05. The car's clock IS accurate. So, the distance from my bed to the car is on a negative time-line. Brilliant.
I was in work at a suitable time. I've been arriving at work suitably for the last couple of weeks. This is not a foolproof system, but it's working for me at the moment.