Basierend auf dieser Frage/Antwort (und das ist grob, nicht getestet, hoffentlich ein Anfang):
class myClassForm(forms.Form):
class Meta:
model = myClass
fields=["name"]
reoccurrance = forms.ChoiceField(label="Reoccurance", choices=(),
widget=forms.Select(attrs={'class':'selector'}))
def __init__(self, *args, **kwargs):
super(myClassForm, self).__init__(*args, **kwargs)
choices = []
for pt in Reoccurance.objects.all():
choices.append((pt.id, unicode(pt.days)))
self.fields['reoccurrance'].choices = choices