Sound activated recording ?

I am interested in running Audacity continuously over a ~9 hour period. I’d like to use the sound activated recording mode, but would need timing information. I’d need to know when each recorded segment began - is there any way to accomplish this with Audacity or is there any means of extracting that data from the resulting file ?

If not, does anyone know of any software that would do this ?

No, Audacity does not do that.
What you really need is surveillance recording software. Google will come up with several possible programs.