Hi,

what you want to accomplish is a little hard and uncommon by the way. My advice: Write a log line with the start time, write later one with the end time. Identify the log lines by process number or other identifier like 'Loops' said before. If you want to see start and end time on one line you could remember the start time and print that together with the end time on the completion event. In this case you get an entry for the start event and an entry for the end event showing start and end time to see the duration (you could even calculate the duration for the reader of the log).

Another approach whould be to log to a database row. But also there you need an unique identifier for the process. Be aware that process numbers get repeated at some time.

Regards
McA