Note : This option becomes active only after the Restrict plots to measurements within a starting time and ending time box is checked , in those processes containing it.Because the first values to be plotted are normally measured before the start of the trial (at time equals 0), this value is typically negative. This value specified here indexes the number of days or weeks before the trial starts, depending on your selection for the Time Scale parameter.Note : All observations taken before the indicated starting time are averaged into one value, which is displayed at the first time.Tip : To change the scale of the slider, right-click on the slider and select from the pop-up menu. Change the upper or lower boundaries in the window that appears, to rescale the slider and click .