I googled this:

“Equinoxes are not day-long events, even though many choose to celebrate all day. Instead, they occur at the moment the Sun crosses the celestial equator, the imaginary line in the sky above Earth’s Equator.

At this instant, Earth's rotational axis is neither tilted away from nor towards the Sun.

Earth's axial tilt is to blame.

In 2019, the Sun's crosses the celestial equator from north to south on September 23, at 07:50 UTC. Because of time zone differences, the equinox will take place on September 22, 2019 at locations that are at least 12 hours or more behind UTC. These include the uninhabited Baker Island and Howland Island.”

But I looked it up and our equinox won’t take place until Monday, the 23rd. So enjoy summer this weekend.