Why Do Scheduled Posts on X Sometimes Publish at the Wrong Time?

I’ve had a couple of posts scheduled on X appear an hour earlier than I expected. The time in the composer looked right, and the account’s usual posting schedule hasn’t changed.

Could this be a timezone setting, a daylight-saving-time mismatch, or something about how X handles scheduled posts? I’m curious whether the time shown in the scheduler follows the device, browser, or account settings—and what’s the best way to verify the scheduled post time before relying on it.