Difference Between Two Dates in Android - CheckIn & CheckOut

"Jai Saraswati Maa"
Hi..... Dear All we are trying to provide here some examples  of Android App Related....
Hope you would Like..........
This example will display the date difference
We are using Android Studio 1.5.1
Minimum API 19 and Target API is 23
Credit goes to Vipul Walia (Student)
 A- Basic Layout 

B - Layout file activity_main.xml is 

<?xml version="1.0" encoding="utf-8"?>

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   

     xmlns:tools="http://schemas.android.com/tools"    

     android:layout_width="match_parent"    

     android:layout_height="match_parent"   

     android:orientation="vertical"    

     tools:context="com.exam.ravi.datedifferenceex1.MainActivity">

    <Button        

       android:id="@+id/changeDate"  

       android:layout_width="match_parent" 

       android:layout_height="wrap_content"   

       android:text="Check-In-Date"      

       android:layout_gravity="center_horizontal"  

       android:layout_marginLeft="15dp" 

       android:layout_marginRight="15dp"        

       android:layout_marginTop="15dp" />

    <TextView     

        android:id="@+id/Output" 

        android:layout_width="wrap_content"      

        android:layout_height="wrap_content"     

        android:text=""        

        android:hint="M-D-YYYY"        

        android:textAppearance="?android:attr/textAppearanceLarge"      

        android:layout_gravity="center_horizontal"     

        android:layout_marginTop="20dp" />

    <Button        

   android:id="@+id/changeDate1"        android:layout_width="match_parent"     

   android:layout_height="wrap_content"        android:text="Check-Out-Date"        

   android:layout_gravity="center_horizontal"        android:layout_marginTop="15dp"        

   android:layout_marginLeft="15dp"        android:layout_marginRight="15dp" />

    <TextView 

       android:id="@+id/Output2"        android:layout_width="wrap_content"       

       android:layout_height="wrap_content"        android:text=""       

       android:hint="M-D-YYYY"        

       android:textAppearance="?android:attr/textAppearanceLarge" 

       android:layout_gravity="center_horizontal"       

       android:layout_marginTop="20dp" />

    <Button    

    android:layout_width="fill_parent"       

    android:layout_height="wrap_content"        android:text="Difference"      

    android:id="@+id/button"        android:layout_marginTop="20dp"       

    android:onClick="showDiff"        android:layout_marginLeft="15dp"      

    android:layout_marginRight="15dp" />

    <TextView   

     android:id="@+id/output3"        android:layout_width="wrap_content"       

     android:layout_height="wrap_content"        

     android:textAppearance="?android:attr/textAppearanceLarge"       

     android:hint="Difference is"        android:layout_gravity="center_horizontal"      

     android:layout_marginTop="30dp" />

</LinearLayout>

C- MainActivity.java is

package com.exam.ravi.datedifferenceex1;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.Toast;

@SuppressWarnings("ALL")
public class MainActivity extends AppCompatActivity {

     TextView Output1;
     Button changeDate1;
     int year1,year2;
     int month1,month2;
     int day1,day2;
     TextView Output2;
     Button changeDate2;
     TextView Output3;
    static final int DATE_PICKER_ID1 = 111;
    static final int DATE_PICKER_ID2 = 222;
    @Override    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Output1 = (TextView) findViewById(R.id.Output);
        changeDate1 = (Button) findViewById(R.id.changeDate);
        Output2 = (TextView) findViewById(R.id.Output2);
        changeDate2 = (Button) findViewById(R.id.changeDate1);
        Output3 = (TextView) findViewById(R.id.output3);

        changeDate1.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View v) {
                // On button click show datepicker dialog               

                    showDialog(DATE_PICKER_ID1);
            }
        });
        changeDate2.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View v) {
                // On button click show datepicker dialog         

                    showDialog(DATE_PICKER_ID2);
            }
        });
    }
    @Override    protected Dialog onCreateDialog(int id) {
        switch (id) {
            case DATE_PICKER_ID1:
                // open datepicker dialog.                

               // set date picker for year==0,month==0,day==0      

                 // add pickerListener listner to date picker      

               return new DatePickerDialog(this, pickerListener1, 0, 0, 0);
            case DATE_PICKER_ID2:
                // open datepicker dialog.              

                // set date picker for year==0,month==0,day==0      

                // add pickerListener listner to date picker     

            return new DatePickerDialog(this, pickerListener2, 0, 0, 0);
        }
        return null;
    }
        /*  BELOW IS THE FIRST DATEPICKEDIALOG LISTER FOR TAKING DIFFERET DATE    */
    private DatePickerDialog.OnDateSetListener pickerListener1 = new 

                                              DatePickerDialog.OnDateSetListener() 

   {

        // when dialog box is closed, below method will be called.      

  @Override      

          public void onDateSet(DatePicker view, int selectedYear,
                              int selectedMonth, int selectedDay) {

            year1  = selectedYear;
            month1 = selectedMonth;
            day1   = selectedDay;

            // Show selected date           

                  Output1.setText(new StringBuilder().append(month1 + 1)
                    .append("-").append(day1).append("-").append(year1)
                    .append(" "));

        }

    };

    /* BELOW IS THE SECOND DATEPICKEDIALOG LISTER FOR TAKING DIFFERET DATE     */  

  private DatePickerDialog.OnDateSetListener pickerListener2 = new

                                                 DatePickerDialog.OnDateSetListener() 

   {

        // when dialog box is closed, below method will be called.        

    @Override       

       public void onDateSet(DatePicker view, int selectedYear,
                              int selectedMonth, int selectedDay) {

            year2  = selectedYear;
            month2 = selectedMonth;
            day2   = selectedDay;

            // Show selected date          

                Output2.setText(new StringBuilder().append(month2 + 1)
                    .append("-").append(day2).append("-").append(year2)
                    .append(" "));
        }
    };
        // COUNT DAY DIFFERENCE    // WE ASSUME DEFAULT MONTH DAYS 30  

  public void showDiff(View view){
        int Days = 0;
        if(month2 == month1){
            if(day2>day1){
                Days = day2 - day1;
            }
        }
        else if(month2>month1){
            if(day2>day1){
                int m = month2-month1;
                Days = m*30 + (day2 - day1);
            }
        }
        else          

        Toast.makeText(this,"Invalid Out Date",Toast.LENGTH_LONG).show();
        Output3.setText(String.valueOf(Days) + " Days");
    }
}