One instant · September equinox 2026
Everyone makes the same sound at the same time.
Four seconds of an open vowel. Then your own name. Then ten seconds of silence. 16 seconds in total, on every continent at once — and then it is over for six months.
2026-09-23 14:05:00 UTC
The September equinox.
The shape of it
- 00:00
Hold one open vowel — "ah"
Any pitch you can reach comfortably. If you can match 110 Hz, match it. Four seconds. Do not shout.
- 00:04
Say your own name. Once.
Speaking volume. Whatever name you actually answer to.
- 00:06
Then stop.
Ten seconds of silence, wherever you are. This part is not optional — it is the part the recordings are for.
The exact wording is sealed until seven days before. Its SHA-256 is published now, so you can check afterwards that nothing changed. See the hash.
The pitch
110 Hz
Low enough that any voice can reach it. No training, no language.
The instant
14:05 UTC
Fixed by orbital mechanics, not by anybody. It means the same thing everywhere.
Notifications
Two
The directive unseal, and the moment. That is the entire budget, on purpose.
Why your timing will be “wrong”
Sound travels 343 metres per second, so two people 340 metres apart physically cannot hear each other at the same instant. Perfect global simultaneity is not possible and is not the goal. Afterwards the app tells you your own deviation from the global mean, in milliseconds — which is the most interesting thing it will ever tell you about yourself.