Index: boost/date_time/tz_db_base.hpp
===================================================================
--- boost/date_time/tz_db_base.hpp	(revision 83763)
+++ boost/date_time/tz_db_base.hpp	(working copy)
@@ -303,9 +303,16 @@
         tokenizer tokens(rule, sep); // 3 fields
         
         tokenizer_iterator tok_iter = tokens.begin(); 
-        nth = std::atoi(tok_iter->c_str()); ++tok_iter;
-        d   = std::atoi(tok_iter->c_str()); ++tok_iter;
-        m   = std::atoi(tok_iter->c_str());
+        
+        if (tok_iter != tokens.end()) {
+			nth = std::atoi(tok_iter->c_str()); ++tok_iter;
+		}
+        if (tok_iter != tokens.end()) {
+			d   = std::atoi(tok_iter->c_str()); ++tok_iter;
+		}
+		if (tok_iter != tokens.end()) {
+			m   = std::atoi(tok_iter->c_str());
+		}
       }