diff --git a/extra/crontab/crontab.factor b/extra/crontab/crontab.factor
index 329b2982a5..03bb49983c 100644
--- a/extra/crontab/crontab.factor
+++ b/extra/crontab/crontab.factor
@@ -50,10 +50,9 @@ CONSTANT: aliases H{
         [ days-of-week>> [ 0 6 between? ] all? ]
         [ months>> [ 1 12 between? ] all? ]
         [
-            [ days>> 1 ] [ months>> ] bi
-            dup { 2 } sequence= [ drop 29 ] [
-                [ day-counts nth ] map supremum
-            ] if [ between? ] 2curry all?
+            [ days>> 1 ] [ months>> ] bi [
+                { 0 31 29 31 30 31 30 31 31 30 31 30 31 } nth
+            ] map supremum [ between? ] 2curry all?
         ]
         [ minutes>> [ 0 59 between? ] all? ]
         [ hours>> [ 0 23 between? ] all? ]