The short answer is: yes, but it has nothing to do with the equinox. According to a popular myth, on the spring equinox, you can stand an egg on its end due to some gravitational balance between the Earth and the Sun. In reality, there is no gravitational change happening during an equinox that would help an egg balance. And there’s no need for it: you can try this egg-balancing trick any random day of the year. All you need to succeed is a bit of patience.