calendar.py

from calendar import LocaleHTMLCalendar
from datetime import date
from itertools import groupby

from django.utils.html import conditional_escape as esc

class WorkoutCalendar(LocaleHTMLCalendar):

    def __init__(self, workouts, locale):
        super(WorkoutCalendar, self).__init__(locale=locale)
        self.workouts = self.group_by_day(workouts)

    def formatday(self, day, weekday):
        if day != 0:
            cssclass = self.cssclasses[weekday]
            if date.today() == date(self.year, self.month, day):
                cssclass += ' today'
            if day in self.workouts:
                cssclass += ' filled'
                body = ['<ul>']
                for workout in self.workouts[day]:
                    body.append('<li>')
                    body.append('<a href="%s">' % workout.get_absolute_url())
                    body.append(esc(workout.title))
                    body.append('</a></li>')
                body.append('</ul>')
                return self.day_cell(cssclass, '%d %s' % (day, ''.join(body)))
            return self.day_cell(cssclass, day)
        return self.day_cell('noday', '&nbsp;')

    def formatmonth(self, year, month):
        self.year, self.month = year, month
        return super(WorkoutCalendar, self).formatmonth(year, month)

    def group_by_day(self, workouts):
        field = lambda workout: workout.performed_at.day
        return dict(
            [(day, list(items)) for day, items in groupby(workouts, field)]
        )

    def day_cell(self, cssclass, body):
        return '<td class="%s">%s</td>' % (cssclass, body)

views.py

from django.shortcuts import render_to_response
from django.utils.safestring import mark_safe

def calendar(request, year, month):
  my_workouts = Workouts.objects.order_by('my_date').filter(
    my_date__year=year, my_date__month=month
  )
  locale = 'de_DE' # change this to your locale string
  cal = WorkoutCalendar(my_workouts, locale).formatmonth(year, month)
  return render_to_response('my_template.html', {'calendar': mark_safe(cal),})

Hello there, are you still having somewhere this project ? I would be really grateful to see models and your template. Thanks!