Use DateTime

perl -MDateTime -le'print DateTime->from_day_of_year( day_of_year => 5
+, year => 2009 )->day_name'
[download]

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)