Simple steps to calculate difference between two date fields using JavaScript/JQuery In some scenario, we need to calculate the difference between two dates from the client side. Here we are going to demonstrate all about date fields using javascript such as Javascript date field validation for different format, difference between two dates in days, hours, minutes, seconds, years and weeks Very strong and simple Javascript validation for date fields for format dd/mm/yyyy Following javascript function simply verify and return result for checking valid date from client side itself. It will automatically validate leap year entries and return correct result. That means if we pass ’29/02/2011′ to the function it will be return false. If we are passing ’29/02/2012′ to the function it will return true. So we don’t need to bother about the leap year or other complex things. function isValidDate(dateStr) { // Date validation Function // Checks For the following valid Date formats: /