In this case, the worker`s first full-time activity, which will take effect on 25 June 1993, is five days or more, so that we would begin to calculate the six months of essentially uninterrupted operating time from that date. However, since the worker works part-time on 25 December 1993, the first possibility for that worker to contribute would be the next full-time occupation of five days or more, that is to say, from 31 January 1994. The worker would then continue to contribute on the basis of a full-time occupation of five days or more. Since the worker is not a part-time grandfather on 4 July 1994, he would continue to contribute to the pension plan on the basis of a subsequent appointment of 12 hours or more after 4 July 1994. “protection of acquired rights”, i.e. the continued application of existing EU treaties with third countries of which the United Kingdom is a member state of the EU, i.e. the smooth signing of new bilateral free trade agreements with virtually the same conditions. The idea of grandfathering is to say: “As a member of the EU, we already have an agreement with these countries, like Korea, so let`s just agree that we can apply the same agreement between Britain and Korea after Brexit.” It`s a nice idea and, at first glance, very logical. Some countries have declared, at least in principle, their readiness to act on this basis. Imagine that the UK makes the EU-Korea deal grandfathered, which therefore allowed for continued free trade between the UK and Korea. .