public String createMaskFromDatePattern(String datePattern) {
        String symbols = "GyMdkHmsSEDFwWahKzZ";
        String mask = "";
        for (int i = 0; i < datePattern.length(); i++) {
            char ch = datePattern.charAt(i);
            boolean symbolFound = false;
            for (int n = 0; n < symbols.length(); n++) {
                if (symbols.charAt(n) == ch) {
                    mask += "#";
                    symbolFound = true;
                    break;
                }
            }
            if (!symbolFound) {
                mask += ch;
            }
        }
        return mask;
    }