You don't need a stopwatch - just examine the log file (it has time stamps). Then you can share the log with us. Ensure you are using claymore v10.1 or higher.
Okay, got the log file pulled up in notepad but I'm not sure what to look for here. There are some seemingly relevant entries, but I can't quite figure out the start and stop points. Any pointers so I don't have to upload a wall of text?