Added valid property to VoucherModel.

django_lostplaces/lostplaces/models.py

@@ -15,6 +15,7 @@ from django.contrib.auth.models import User
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 from django.core.validators import MaxValueValidator, MinValueValidator
+from django.utils import timezone
 from easy_thumbnails.fields import ThumbnailerImageField
 from easy_thumbnails.files import get_thumbnailer
 from taggit.managers import TaggableManager
@@ -106,6 +107,10 @@ class Voucher(models.Model):
     created_when = models.DateTimeField(auto_now_add=True)
     expires_when = models.DateTimeField()
 
+    @property
+    def valid(self):
+        return timezone.now() <= self.expires_when
+
     def __str__(self):
         return "Voucher " + str(self.pk)