Although it is possible for an organizer to schedule more than 1 webinar for the same date and time, only 1 webinar can actually be run at a time. I

If you need to host multiple webinars that overlap in date and time, then you should ask your account admin to add an additional organizer seat to your account, schedule the second webinar from that account, and host it from a separate computer.

If your account also includes GoToMeeting or GoToTraining, it is possible for you to host a meeting, a webinar and a training at the same time (as long as each session is run from a different computer or mobile device).

If you attempt to run more than one webinar at a time, you will see a "A session is already running" notification. To join the other webinar, you must leave the current one.