diff --git a/seminar/migrations/0049_auto_20190430_2354.py b/seminar/migrations/0049_auto_20190430_2354.py
index 7f374be3..8957b010 100644
--- a/seminar/migrations/0049_auto_20190430_2354.py
+++ b/seminar/migrations/0049_auto_20190430_2354.py
@@ -219,7 +219,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='organizator',
             name='organizuje_od',
-            field=models.DateTimeField(default='1900-01-01T00:00:00', verbose_name='Organizuje od'),
+            field=models.DateTimeField(null=True,blank=True, verbose_name='Organizuje od'),
         ),
         migrations.AddField(
             model_name='organizator',
diff --git a/seminar/migrations/0053_organizator_organizuje_od_do.py b/seminar/migrations/0053_organizator_organizuje_od_do.py
new file mode 100644
index 00000000..b94e8032
--- /dev/null
+++ b/seminar/migrations/0053_organizator_organizuje_od_do.py
@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.20 on 2019-05-16 21:26
+from __future__ import unicode_literals
+
+import datetime as dt
+from django.db import migrations
+
+def rok_to_datetime(apps,schema_editor):
+	Organizator = apps.get_model('seminar','Organizator')
+	for o in Organizator.objects.all():
+		rok = o.organizuje_od_roku
+		if rok:
+			o.organizuje_od = dt.datetime(rok,1,1)
+		rok = o.organizuje_do_roku
+		if rok:
+			o.organizuje_do = dt.datetime(rok,12,31)
+		o.save()
+
+def datetime_to_rok(apps,schema_editor):
+	Organizator = apps.get_model('seminar','Organizator')
+	for o in Organizator.objects.all():
+		o.organizuje_od_roku = o.organizuje_od.year
+		o.organizuje_do_roku = o.organizuje_do.year
+		o.save()
+	
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('seminar', '0052_user_to_organizator'),
+    ]
+
+    operations = [
+		migrations.RunPython(rok_to_datetime, datetime_to_rok),
+    ]
diff --git a/seminar/models.py b/seminar/models.py
index 1ab29ee8..8466f5a9 100644
--- a/seminar/models.py
+++ b/seminar/models.py
@@ -467,7 +467,7 @@ class Organizator(SeminarModelBase):
 		editable=False
 	)
 
-	organizuje_od = models.DateTimeField('Organizuje od', blank=False, null=False, default="1900-01-01T00:00:00")
+	organizuje_od = models.DateTimeField('Organizuje od', blank=True, null=True)
 	
 	organizuje_do = models.DateTimeField('Organizuje do', blank=True, null=True)