I am applying for a 2-year family visit visa for my parents. Should I enter the date of leaving for 6 months or will it be for 2 years since they will be allowed a maximum of 6 months per stay? What should I give ad the date they will leave the UK? Is it 6 months or 2 years?
Enter the date in which you plan to leave the UK after your first intended visit, whether the first visit is 1 day or 6 months.
The decision for the multiple entry family visit visa will usually be based on other criteria, such as proof of ties to your home country, financial status, etc. and the dates are really irrelevant except for the visa validity date.