A $(()) kifejezésekben meg lehet adni a konstansokhoz a számrendszert, amelyben értelmezni óhajtjuk azokat. Próbáld ezt: $((10#$DAY % 3)).
Constants with a leading 0 are interpreted as octal numbers. A leading
0x or 0X denotes hexadecimal. Otherwise, numbers take the form
[base#]n, where the optional base is a decimal number between 2 and 64
representing the arithmetic base, and n is a number in that base. If
base# is omitted, then base 10 is used. The digits greater than 9 are
represented by the lowercase letters, the uppercase letters, @, and _,
in that order. If base is less than or equal to 36, lowercase and
uppercase letters may be used interchangeably to represent numbers
between 10 and 35.