public class timeConversation { static String timeConversion(String s) { String [] tempArray = s.split(":"); String hours = tempArray[0]; String minutes = tempArray[1]; String seconds = tempArray[2].substring(0, 2); int tempHours; if (tempArray[2].substring(2, 4).equalsIgnoreCase("PM")) { if (Integer.parseInt(hours) < 12) { tempHours = Integer.parseInt(hours); tempHours += 12; hours = Integer.toString(tempHours); } } if (tempArray[2].substring(2, 4).equalsIgnoreCase("AM")) { if (Integer.parseInt(hours) == 12) { hours = "00"; } } return hours + ":" + minutes + ":" + seconds; } public static void main(String[]args){ String s = "07:05:45PM"; //sample test case System.out.println(timeConversion(s)); } }