/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

import java.time.*;
import java.time.format.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{

    String s = 
    LocalTime.MIN.plus(
        Duration.between( 
            LocalTime.of( 12 , 5 , 0 ) ,
            LocalTime.of( 12 , 7 , 0 ) 
        )
    ).toString();
    System.out.println( s );

    LocalTime start = LocalTime.now( ZoneId.of( "America/Montreal" ) );
    LocalTime stop = start.plusMinutes( 7 );
    Duration d = Duration.between( start , stop );
    LocalTime result = LocalTime.MIN.plus( d );  // I do *not* recommend abusing `LocalTime` this way. Use `Duration` instead.
    DateTimeFormatter f = DateTimeFormatter.ISO_LOCAL_TIME ;
    String output = result.format( f );
    System.out.println( "output: " + output );

	}
}