diff --git a/.mailmap b/.mailmap
index 95a60d9e3a16fc35766b246638d8c96d07a3f7e0..5d0c0b511a2d9d83655c0ff977ef165cda5bc545 100644
--- a/.mailmap
+++ b/.mailmap
@@ -1,4 +1,5 @@
-Jean-Sébastien Caux <git@jscaux.org> J.-S. Caux <J.S.Caux@uva.nl> 
+Jean-Sébastien Caux <git@jscaux.org> J.-S. Caux <J.S.Caux@uva.nl>
+Jean-Sébastien Caux <git@jscaux.org> Jean-Sebastien Caux <J.S.Caux@uva.nl>
 Jean-Sébastien Caux <git@jscaux.org> Jean-Sebastien Caux <jscaux@ABACUS.local>
 Jean-Sébastien Caux <git@jscaux.org> Jean-Sebastien Caux <jscaux@vpn-staff-146-50-69-84.vpn.uva.nl>
 SciPost techsupport <techsupport@scipost.org>
diff --git a/scipost_django/common/converters.py b/scipost_django/common/converters.py
index 76a8a94c268bb35644fa86a89147aba5d4d00362..296286fc42967c8e8d2d8d31668fd48218fc9d68 100644
--- a/scipost_django/common/converters.py
+++ b/scipost_django/common/converters.py
@@ -16,11 +16,11 @@ class FourDigitYearConverter:
         return int(value)
 
     def to_url(self, value):
-        return '%04d' % value
+        return '%04d' % int(value)
 
 
 class TwoDigitMonthConverter:
-    regex = '(0[1-9]{1})|(1[1-2]{1})'
+    regex = '0[1-9]|1[0-2]'
 
     def to_python(self, value):
         return int(value)
@@ -30,7 +30,7 @@ class TwoDigitMonthConverter:
 
 
 class TwoDigitDayConverter:
-    regex = '([0-2]{1}[1-9])|30|31'
+    regex = '0[1-9]|[1-2][0-9]|3[0-1]'
 
     def to_python(self, value):
         return int(value)