I'm using matplotlib.pyplot.plot to plot values from CSV files where
the x axis data are datetime objects. This works well except for two
* The time ranges are large (one-second samples over a period of
several days) and I find the x axis label formats are often
inappropriate to the scale. How to I control the format of
the x axis labels?
* Samples are only collected for part of the time each day, say
from 01:00 to 15:00. How can I elide the gaps and perhaps
plot a vertical line to signify the elided gaps?