Month/Year picker

As a small enhancement it was requested that the startdate could be a month/year picker instead of a day/month/year picker; the exact day is not needed information and it might reduce stress for the user ;)

Start by locating the startdate field and the current day/month/year picker in the Django application. Trace where the field is defined and rendered, then check the existing form behavior; done means users can select only a month and year without requiring an exact day.

Written by the indexing model from the issue text.