The OSI post that the author links to specifies the voting deadline in GMT (effectively UTC) in the sentence immediately preceding the timeline diagram.
So it can be reasonably inferred that they’re generally using GMT/UTC in the rest of their timeline, rather than AOE, UTC+14 or anything else out of the ordinary.
The worst _reasonable_ case is UTC. Nobody is thinking UTC+14.
> I agree with the author: the timezone of the organisation is what I'd expect.
If the job was a local office job, I’d expect a local time zone. But the board of directors isn’t restricted to California or even the USA.