Civilian time format to Military time format in Java

This Java code can convert Civilian time format to Military time format without using any specialized classes.

import java.util.Scanner;
/**
*
* @author Md. Asif Bin Khaled
*/
public class TimeConversion {

public static void main(String[] args) {
Scanner yo = new Scanner(System.in);
String date_in_12 = yo.nextLine();
String[] tokens = date_in_12.split(":");
String date_in_24 = "";
String am_pm = tokens[2];
if (tokens[2].endsWith("PM")) {
if (tokens[0].equals("12")) {
date_in_24 += tokens[0];
} else {
date_in_24 += (Integer.parseInt(tokens[0]) + 12) % 24;
}

} else {
date_in_24 += tokens[0];
}
if (tokens[2].endsWith("PM")) {
tokens[2] = tokens[2].replace("PM", "");
} else {
tokens[2] = tokens[2].replace("AM", "");
}
if (tokens[0].equals("12") && am_pm.endsWith("AM")) {
date_in_24 = "00:" + tokens[1] + ":" + tokens[2];
} else {
date_in_24 += ":" + tokens[1] + ":" + tokens[2];
}
System.out.println(date_in_24);

}
}
Link to Github: https://github.com/mdasifbinkhaled/Java/blob/master/Time%20Conversion/src/time/conversion/TimeConversion.java