How to handle calendar for "departure" box and "return" box in Selenium?

Question

How to handle the calendar for the departure box and return box in selenium. Please check my code once website: https://www.goibibo.com/

public class goibibo {
    private static WebDriver driver = null;
    public static void main(String[] args) throws InterruptedException  {
        // TODO Auto-generated method stub
        WebDriver driver = new ChromeDriver();
        driver.get("https://www.goibibo.com/");
        driver.manage().window().maximize();
        new WebDriverWait(driver, 20).until(ExpectedConditions.elementToBeClickable(By.xpath("//input[@id='gosuggest_inputSrc']"))).sendKeys("A");
        Thread.sleep(1000);
        List<WebElement> myList = new WebDriverWait(driver, 20).until(ExpectedConditions.presenceOfAllElementsLocatedBy(By.xpath("//div[@class='dib marginL10 pad0 textOverflow width90']/div/span")));
        for (int i = 0; i < myList.size(); i++)
        {
                System.out.println(myList.get(i).getText());
                if (myList.get(i).getText().equals("Ahmedabad"))
                {
                    myList.get(i).click();
                    break;
                }
            }
        new WebDriverWait(driver, 20).until(ExpectedConditions.elementToBeClickable(By.xpath("//*[@id=\"gosuggest_inputDest\"]"))).sendKeys("Mum");
        Thread.sleep(1000);
        List<WebElement> Dept = new WebDriverWait(driver, 20).until(ExpectedConditions.presenceOfAllElementsLocatedBy(By.xpath("//div[@class='dib marginL10 pad0 textOverflow width90']/div/span")));
        for (int j = 0; j < Dept.size(); j++)
        {
                System.out.println(Dept.get(j).getText());
                if (Dept.get(j).getText().equals("Mumbai"))
                {
                    Dept.get(j).click();
                    break;
                }
        }

        //Thread.sleep(3000);
        //driver.switchTo().frame("notification-frame-~2514428c7");
        //driver.findElement(By.xpath("//i[@class='wewidgeticon we_close']")).click();
        //pop-up frame
        WebDriverWait wait = new WebDriverWait(driver, 5);
        wait.until(ExpectedConditions.frameToBeAvailableAndSwitchToIt(By.xpath("//iframe[starts-with(@name ,'notification-frame-')]")));
        WebElement element=wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//i[contains(@class ,'wewidgeticon')]")));
        element.click();

        //dates
        Thread.sleep(5000);
        driver.findElement(By.xpath("//*[@id=\"searchWidgetCommon\"]/div[1]/div[1]/div[1]/div/div[6]/input")).click();

        List<WebElement> allDates=driver.findElements(By.xpath("//*[@id=\"searchWidgetCommon\"]/div[1]/div[1]/div[1]/div/div[6]/div/div"));

        for(WebElement ele:allDates)
        {

            String date=ele.getText();

            if(date.equalsIgnoreCase("28"))
            {
                ele.click();
                break;
            }

        }

    }

}

Exception in thread "main" org.openqa.selenium.NoSuchElementException: no such element: Unable to locate element: {"method":"xpath","selector":"//*[@id="searchWidgetCommon"]/div[1]/div[1]/div[1]/div/div[6]/input"}