Make timestamps on zephyrs timezone-aware.

This will avoid Daylight Saving Time issues and resolves a Django
warning about using naive datetime objects ("RuntimeWarning:
DateTimeField received a naive datetime").

This adds a dependency on python-tz.

https://docs.djangoproject.com/en/dev/topics/i18n/timezones/

(imported from commit 10e432a67e2bcd014a0cedf4423a162609873825)

setup-server

@@ -2,7 +2,7 @@
 resize2fs /dev/xvda1
 apt-get update
 apt-get upgrade
-apt-get install sudo emacs screen git
+apt-get install sudo emacs screen git python-tz
 
 cat >>/etc/apt/sources.list <<EOF
 deb http://backports.debian.org/debian-backports squeeze-backports main

zephyr/management/commands/populate_db.py

@@ -1,4 +1,5 @@
 from django.core.management.base import NoArgsCommand
+from django.utils.timezone import utc
 
 from django.contrib.auth.models import User
 from zephyr.models import Zephyr, UserProfile, ZephyrClass, Recipient
@@ -47,7 +48,7 @@ class Command(NoArgsCommand):
             new_zephyr.recipient = Recipient.objects.get(id=random.choice(recipients))
             zephyr_class = ZephyrClass.objects.get(pk=new_zephyr.recipient.pk)
             new_zephyr.instance = zephyr_class.name + str(random.randint(1, 3))
-            new_zephyr.pub_date = datetime.datetime.utcnow()
+            new_zephyr.pub_date = datetime.datetime.utcnow().replace(tzinfo=utc)
             new_zephyr.save()
 
         self.stdout.write("Successfully populated test database.\n")

zephyr/views.py

@@ -111,7 +111,7 @@ def personal_zephyr(request):
     new_zephyr.content = request.POST['new_personal_zephyr']
     new_zephyr.recipient = recipient
     new_zephyr.instance = u''
-    new_zephyr.pub_date = datetime.datetime.utcnow()
+    new_zephyr.pub_date = datetime.datetime.utcnow().replace(tzinfo=utc)
     new_zephyr.save()
 
     return HttpResponseRedirect(reverse('zephyr.views.home'))
@@ -136,7 +136,7 @@ def zephyr(request):
     new_zephyr.content = request.POST['new_zephyr']
     new_zephyr.recipient = recipient
     new_zephyr.instance = request.POST['instance']
-    new_zephyr.pub_date = datetime.datetime.utcnow()
+    new_zephyr.pub_date = datetime.datetime.utcnow().replace(tzinfo=utc)
     new_zephyr.save()
 
     return HttpResponseRedirect(reverse('zephyr.views.home'))