How to get ros time within extension

Two things I’d like to understand about ROS2Bridge:

  1. When I create a RosClock prim in my simulation (simTime=True) and start it using the play button, it starts publishing to the /clock topic, beginning with 0. When stopping the simulation and restarting, it will not reset to 0, but continue with the simulation time last published. Can I reset the ros clock without restarting Isaac Sim?

  2. How can I retrieve the simulation time from within an extension? Up to now I was only able to get the time from the timeline extension, but it differs from the ros clock and is reset each time I restart the simulation.

Thanks a lot
Bruno