Fixed bug with regions not working correctly after load() with time series

Hello,
I've encountered a bug with rectangular regions in a time series.
The problem was that after passing data to load() and specifying regions via myChart.region([...]) these regions were not visible. When I looked into generated HTML, regions were there but had weird positions: around -9000000, because it used parsed Date for calculations - probably casted to string, not numeric values of Date. Placing valueOf() resolved this problem.

That's one thing - another one could be an example of using regions with timeseries, because at first I didn't know my start and end values should be based on time (I tried to pass chart point id's, like in the example on website)