With Genelec Classic 2-way monitors, approximately time is 60 minutes.
With the latest F series subwoofers, the time is approximately 45min.

M030 and M040, approximately 30 minutes.

Tolerance is +-20% and each of the monitors can go to sleep state slightly different time.

With 83xx -monitors and 73xx subwoofers, it is possible to adjust the ISS sensitivity and sleep delay time from the GLM settings.