From b611d63975d4599946189ba95faa0d30d77e01e8 Mon Sep 17 00:00:00 2001
From: Raphael Michel <mail@raphaelmichel.de>
Date: Wed, 13 Sep 2017 16:20:54 +0200
Subject: [PATCH] ModelRelativeDateTimeField: Deal with None values

---
 src/pretix/base/reldate.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/pretix/base/reldate.py b/src/pretix/base/reldate.py
index 870493ee7..cf80b595c 100644
--- a/src/pretix/base/reldate.py
+++ b/src/pretix/base/reldate.py
@@ -306,6 +306,8 @@ class ModelRelativeDateTimeField(models.CharField):
         return value
 
     def from_db_value(self, value, expression, connection, context):
+        if value is None:
+            return None
         return RelativeDateWrapper.from_string(value)
 
     def formfield(self, **kwargs):