Vertical markers at start of week, month

[Eike]

Vertical markers at the start of the week, month, year

The right thing would be to print the markers depending on the zoom level.

These markers could probably be implemented as ticks on the X-axis. Look at:
           matplotlib.dates.WeekdayLocator,
           matplotlib.dates.RRuleLocator,
           matplotlib.dates.rrulewrapper

[Eike (eike-welk)]

Each axis of the diagram has a attribute `grid`. It probably draws a horizontal or vertical line across the diagram, at the location of the ticks.

http://matplotlib.sourceforge.net/users/artists.html