[FIX]pms: property date timezone without user

pms/models/pms_property.py

@@ -395,6 +395,7 @@ class PmsProperty(models.Model):
 
     def date_property_timezone(self, dt):
         self.ensure_one()
+        if self.env.user:
             tz_property = self.tz
             dt = pytz.timezone(tz_property).localize(dt)
             dt = dt.replace(tzinfo=None)