<Tr> <Td> 2018 </Td> <Td> 25 March </Td> <Td> 28 October </Td> </Tr> <Tr> <Td> 2019 </Td> <Td> 31 March </Td> <Td> 27 October </Td> </Tr> <Tr> <Td> 2020 </Td> <Td> 29 March </Td> <Td> 25 October </Td> </Tr> <Tr> <Td> 2021 </Td> <Td> 28 March </Td> <Td> 31 October </Td> </Tr>

When did the uk not change the clocks