<Tr> <Th> 2019 </Th> <Td> 20 </Td> <Td> 21: 58 </Td> <Td> 21 </Td> <Td> 15: 54 </Td> <Td> 23 </Td> <Td> 07: 50 </Td> <Td> 22 </Td> <Td> 04: 19 </Td> </Tr> <Tr> <Th> 2020 </Th> <Td> 20 </Td> <Td> 03: 50 </Td> <Td> 20 </Td> <Td> 21: 44 </Td> <Td> 22 </Td> <Td> 13: 31 </Td> <Td> 21 </Td> <Td> 10: 02 </Td> </Tr> <P> An equinox is commonly regarded as the moment the plane of Earth's equator passes through the center of the Sun's disk, which occurs twice each year, around 20 March and 22 - 23 September . In other words, it is the point in which the center of the visible sun is directly over the equator . This simplified, but incorrect, understanding of Earth's orbital motion can lead to errors of up to 69 seconds from the actual time of equinox . </P> <P> The instants of the equinoxes are currently defined to occur when the ecliptic longitude of the Sun is either 0 ° or 180 ° . As the true motion of the Earth is affected by the gravitational pull of the Sun and Moon (and to lesser extent the other planets), there are tiny (up to 11⁄4 arcsecond) variations of the Sun's ecliptic latitude (discussed in section below) that may mean the Sun's center is not precisely over the equator at the moment of equinox . </P>

During which two months (equinoxes) do all locations on earth experience 12 hours of daylight