Posting hours and time zone
Sets the window of hours, in your saved time zone, that automatic and queued posts are allowed to go out in.
Settings → Posting schedule shows your Posting window (or "Posting hours and timezone"), with an "Edit hours in Schedule" link that opens the editor on the Schedule tab.
The editor has a from time, an until time, and a Time zone picker. Leaving either time set to off means any time — no window is enforced on that side. Posting hours and daily limits are both measured in the time zone you pick here, which may be different from your device's own time zone.
Everything EverySqueeze posts for you waits for these hours: a post that's otherwise ready but falls outside the window holds until the window opens. Changing your saved hours does not rewrite the date and time already chosen for a post you scheduled individually — it only affects future automatic and paced posts.
See Why a post hasn't gone out for how a held-for-hours post is shown, and Minimum gap between posts for the spacing rule that works alongside the window.