In NeuroExplorer 1D Data Viewer, timestamps are shown as tick marks:
If you zoom out the time scale (you can do this by rotating the mouse wheel while pressing Ctrl button), NeuroExplorer uses color to indicate the number of tick marks in each pixel:
Several NeuroExplorer users asked me what is the color scale used in 1D Viewer. Starting with version 5.110 (released in December, 2017), NeuroExplorer displays the appropriate color scale:
The color scale values are spikes per second. You can set the color scale options using Edit Color Scale Properties context menu command (right-click in 1D Viewer to invoke its context menu).