Java tutorial
//package com.java2s; public class Main { public static String getDayFromNumber(int day) { if (day < 0 || day > 30) throw new IllegalArgumentException(); if (day <= 10) return String.valueOf(Character.toChars(1487 + day)); else if ((day >= 11 && day <= 14) || (day >= 16 && day <= 19)) { char yod = Character.toChars(1497)[0]; return String.valueOf(new char[] { yod, Character.toChars(1487 + (day - 10))[0] }); } else if (day == 15 || day == 16) { char tet = Character.toChars(1498)[0]; return String.valueOf(new char[] { tet, Character.toChars(1487 + (day - 9))[0] }); } else if (day == 20) { return String.valueOf(Character.toChars(1499)[0]); } else if (day >= 21 && day <= 29) { char chaf = Character.toChars(1499)[0]; return String.valueOf(chaf + Character.toChars(1487 + (day - 20))[0]); } else { return String.valueOf(Character.toChars(1500)[0]); } } }