The concept of the cooling off period or days of grace in timeshare refer to the time between the purchase of your unit and your last opportunity to change your mind. You are give some days in which to think about your purchase and ensure that you are happy with the timeshare resort and property that you have chosen. After the cooling off period you will not be able to cancel your timeshare, although you may be able to upgrade your property or change your timeshare contract for a more elite plan.
The cooling off period gives you the chance to think about your finances and enjoy the destination where you have bought the timeshare to give you peace of mind that you have made the right decision. This is the only time that you will be able to cancel your timeshare unless you have been involved in a deliberate timeshare fraud or scam. In those cases you will have to prove that your bought a timeshare under false pretenses.
The length of the cooling off period will depend on the country where the timeshare was sold and the law that regulate timeshare there. The cooling off times is usually between 7 and 14 days, but you should check with the timeshare seller.