C :

#include<stdio.h>
int main()
{
	int a,b,c,d,e;
	scanf("%d:%d",&a,&b);
	scanf("%d:%d",&c,&d);
		e=(c-a)*60+(d-b-1);
	printf("%d",e);
	return 0;		
}

C++ :

#include <stdio.h>
int main ( )
{
    int a,b,c,d,n,m,x;
    scanf("%d:%d%d:%d",&a,&b,&c,&d);
    n=(c-a)*60;
    m=d-b-1;
    x=n+m;
    printf("%d",x); 
    return 0;
} 

Java :

import java.util.Scanner;
public class Main {
    public static void main(String [] agrs){
        Scanner input=new Scanner(System.in);
        String s1=input.nextLine();
        String[] a=s1.split(":");
        int h1=Integer.parseInt(a[0]);
        int m1=Integer.parseInt(a[1]);
        String s2=input.nextLine();
        String[] b=s2.split(":");
        int h2=Integer.parseInt(b[0]);
        int m2=Integer.parseInt(b[1]);
        System.out.println(((h2-h1)*60)+m2-m1-1);
    }
}

Python :

# coding=utf-8
#python2
a,b = raw_input().split(':')
a = int(a)
b = int(b)
x,y = raw_input().split(':')
x = int(x)
y = int(y)
print((x-a)*60+y-b-1)

C# :

using System;
using System.Collections.Generic;
using System.Diagnostics.SymbolStore;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main()
        {
            //int[] days = { 31,28,31,30,31,30,31,31,30,31,30,31};
            string[] a1 = Console.ReadLine().Split(':');
            int m1 = Convert.ToInt32(a1[0]);
            int d1 = Convert.ToInt32(a1[1]);
            string[] b1 = Console.ReadLine().Split(':');
            int m2 = Convert.ToInt32(b1[0]);
            int d2 = Convert.ToInt32(b1[1]);
            int y = 0;
            for (int i = m1; i < m2; i++)
            {
                y += 60;
            } 
                y += d2 - d1 - 1;
                Console.WriteLine(y);
                Console.ReadKey();

            

        }
    }
}