21 September 2023
Are we there yet? Have we reached the equinox?
In Pittsburgh the winter solstice invariably arrives on 21 December, but the 21st never works for the autumnal equinox.
As an astronomical event, the equinox arrives everywhere on Earth at exactly the same moment but is expressed as different dates and times because of longitude and time zones. Hawaii’s equinox is on the 22nd while Paris and Johannesburg have the same date and time because of time zones.
| Universal Time | 23 Sep, 6:50AM UTC |
| Pittsburgh | 23 Sep, 2:50AM EDT |
| Honolulu, HI | 22 Sep, 8:49PM HST |
| Tokyo | 23 Sep 22, 3:49PM JST |
| Paris | 23 Sep, 8:49AM CET |
| Johannesburg, SA | 23 Sep, 8:49AM SAST |
For most of the Earth this month’s equinox will occur on the 23rd. When it does everyone’s sunset will be exactly west, just like the photo above.
Learn how this works at …
(photo from Wikimedia Commons)