To provide current date and timestamp as an input to sendkeys method

How about:

Date todaysDate = new Date();
def formattedDate = todaysDate.format("dd-MMM-yyyy HH:MM");

WebUI.setText(findTestObject('myPage/myDate'), formattedDate)

WebUI.verifyElementAttributeValue(findTestObject('myPage/myDate'), "value", formattedDate, 10)