--- a/src/parser/attack_scanner.l
+++ b/src/parser/attack_scanner.l
@@ -72,7 +72,7 @@
 
 
 MONTH       (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)
-DAYNO       [1-9][0-9]?
+DAYNO       [0-9][0-9]?
 HOUR        (0|1)[0-9]|2[0-4]
 MINPS       [0-5][0-9]
 WORD        [a-zA-Z0-9][-_a-zA-Z0-9]+