This code performs date selection in a calendar.

CommonFunctions.java

public static void calendarHandling(String date, WebDriver driver) {

		// elements for clicking calendar buttons
		String PrevButtonM = "//div[@id='ui-datepicker-div']/descendant::div[@class='header']/a[@title='Prev']";
		String NextButtonM = "//div[@id='ui-datepicker-div']/descendant::div[@class='header']/a[@title='Next']";
		String currentReturnedYear = "//div[@id='ui-datepicker-div']/descendant::div[@class='monthBlock first']//div[@class='title']/span[@class='ui-datepicker-year']";
		String returnedMonth = "//div[@id='ui-datepicker-div']/descendant::div[@class='monthBlock first']//div[@class='title']/span[@class='ui-datepicker-month']";

		date = date.trim();
		String DateArr[] = date.split("/");
		int Day = Integer.parseInt(DateArr[0]);
		int month = Integer.parseInt(DateArr[1]);
		int Year = Integer.parseInt(DateArr[2]);

		HashMap<String, Integer> calendarMonths = new HashMap<String, Integer>();

		calendarMonths.put("January", 1);
		calendarMonths.put("February", 2);
		calendarMonths.put("March", 3);
		calendarMonths.put("April", 4);
		calendarMonths.put("June", 6);
		calendarMonths.put("July", 7);
		calendarMonths.put("August", 8);
		calendarMonths.put("September", 9);
		calendarMonths.put("October", 10);
		calendarMonths.put("November", 11);
		calendarMonths.put("December", 12);

		int retYear;

		try {
			System.out.println(Day + "-" + month + "-" + Year);
			do {
// return the Year displaying on the application calendar
				retYear = Integer.parseInt(driver.findElement(By.xpath(currentReturnedYear)).getText());

				if (retYear < Year) {
//taking calendar to year provided by user
					driver.findElement(By.xpath(NextButtonM)).click();

				}
				if (retYear > Year) {
//year less than current year displayed on calendar can be propagated
					throw new RuntimeException("Year cannot be less than current year");

				}

// If same checking for the date input by user and comparing with that of
// calendar display

				int retmonthcount = 0;
				if (retYear == Year) {
					for (int i = 1; i <= 12; i++) {

// fetching current calendar month displayed
						String returnedmonth = driver.findElement(By.xpath(returnedMonth)).getText();
						if (calendarMonths.containsKey(returnedmonth))
							retmonthcount = calendarMonths.get(returnedmonth);

// propagating to future months as per given input
						if ((retmonthcount < month) && (driver.findElement(By.xpath(NextButtonM)).isDisplayed())) {

							driver.findElement(By.xpath(NextButtonM)).click();

						}
//propagating to earlier months as per provided input
						if ((retmonthcount > month) && (driver.findElement(By.xpath(PrevButtonM))).isDisplayed()) {

							driver.findElement(By.xpath(PrevButtonM)).click();

						} else if (retmonthcount == month) {
							try {
								driver.findElement(By.xpath(
										"//div[@id='ui-datepicker-div']/descendant::div[@class='monthBlock first']//a[text()='"
												+ Day + "']"))
										.click();
								break;

							} catch (Exception e) {
								throw new Exception("You may have entered a wrong date");
							}
						}
					}

				}

			} while (retYear != Year);

		} catch (Throwable e) {
			// e.printStackTrace();
			System.out.println(e.getMessage());
			// System.out.println("Invalid input Date as per Site Calendar");
			// System.out.println());
		}
	}