Trying to build a regular expression to check pattern

Question

a) Start and end with a number
b) Hyphen should start and end with a number
c) Comma should start and end with a number
d) Range of number should be from 1-31

Answer 1

Using the same logic in my previous answer but limiting the range

A becomes [1-9]\d|3[01] B becomes ([1-9]\d|3[01])|(([1-9]\d|3[01])-([1-9]\d|3[01]))

Overall expression

(([12]\d|3[01])|(([12]\d|3[01])-([12]\d|3[01])))(,(([12]\d|3[01])|(([12]\d|3[01])-([12]\d|3[01]))))*