Mostly a south Indian festival, Vishu is the dawn of a new astronomical year, and the day marks the first day of the Malayalam month of Medam that corresponds with April in the Gregorian calendar.
They will issue a refund and depending on the method of refund, this should be completed within 28 days. You will be asked to return all documentation regarding the gap insurance you have cancelled and the cover will cease at this point.
If you e-filed your return and are expecting a refund, you should get it pretty quickly. The Internal Revenue Service says most refunds are issued in less than 21 days. That's assuming your tax return is complete, has no errors and is not affected by identity theft or fraud. So if it's been more than 21 days and you haven't seen any sign of it, the IRS gives you several ways to track it down.