The Time Slider shows the current time stretching value, refreshing it periodically each one second. It also allow the user to alter the time stretching factor by grabbing the slider (click on the slider with the left button and keep it pressed) and moving it to left or to right:
The time stretching factors shown below the slider are related to the coarse (default) time resolution. If the fine time adjustment flag is set, the leftmost slider position corresponds approx. To x2 and the rightmost to approx. :2