question: private static int parseNumber ( CharSequence offsetId , int pos , boolean precededByColon ) { if ( precededByColon && offsetId . charAt ( pos - 1 ) != ':' ) { throw new DateTimeException ( "Invalid ID for ZoneOffset, colon not found when expected: " + offsetId ) ; } char ch1 = offsetId . charAt ( pos ) ; char ch2 = offsetId . charAt ( pos + 1 ) ; if ( ch1 < '0' || ch1 > '9' || ch2 < '0' || ch2 > '9' ) { throw new DateTimeException ( "Invalid ID for ZoneOffset, non numeric characters found: " + offsetId ) ; } return ( ch1 - 48 ) * 10 + ( ch2 - 48 ) ; }
target:  Parse a two digit zero-prefixed number.