<Tr> <Th> Observances </Th> <Td> Comedy </Td> </Tr> <Tr> <Th> Date </Th> <Td> April 1 </Td> </Tr> <Tr> <Th> Next time </Th> <Td> 1 April 2018 (2018 - 04 - 01) </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> Annual </Td> </Tr>

Who is believed to be the person that came up with the idea of labor day