public static void main(String[] args) {
        String s = "00:00-08:30";
        //String s = "00:00-08:30#00:00-08:30#10:00-20:00";
        Pattern p = Pattern.compile("((\\d{2}:\\d{2}-\\d{2})?:\\d{2}#?)+");
        Matcher m = p.matcher(s);
        if(m.matches()){
            System.out.println(m.group());
        }

    }

------解决方案--------------------
Java code

    public static boolean checkStr(String str){
        if(str == null || "".equals(str.trim()))
            return false;
        String[] arr = str.split("#");
        for (String string : arr) {
            if(!string.matches("\\d{2}:\\d{2}-\\d{2}:\\d{2}"))
                return false;
        }
        return true;
    }

------解决方案--------------------
^\d{2}:\d{2}-\d{2}:\d{2}(#\d{2}:\d{2}-\d{2}:\d{2})*$

------解决方案--------------------
为什么都在这里\d{2}   时间要么12小时制 要么24小时制

\d{2} 是不合法的。

^([01][\d]|2[0-4]):([0-5][\d]|60)[#]([01][\d]|2[0-4]):([0-5][\d]|60)$

------解决方案--------------------

^([01][\d]|2[0-4]):([0-5][\d]|60)-([01][\d]|2[0-4]):([0-5][\d]|60)[#]([01][\d]|2[0-4]):([0-5][\d]|60)-([01][\d]|2[0-4]):([0-5][\d]|60)$