How the hours are read

Each day takes up to three spans, written as times such as 09:00 to 17:00. A closing time that is not after the opening time runs past midnight, so 22:00 to 02:00 is open from late evening to the small hours of the next day. A day left empty is closed. The time zone is your site’s, set under Settings → General. Try a week below:

Is the button open at that moment?

Write a week, a time zone and a moment in UTC, and see whether Pro would show the button, or what the menu would say. Nothing you type leaves this page.

Why it is worked out in the browser

A page kept in a cache is the same for everyone, at every hour. If the server decided whether you are open, the cached copy would say whatever was true when it was made. So Pro compares your hours, in your site’s zone, with the clock on the visitor’s device, in the visitor’s browser. The caching guide says why that matters.

Two limits, said plainly

A visitor who arrives while you are closed may see the button for a moment, before the small script hides it, because the cached page has it. We measured it in Chrome: about one frame (8 milliseconds) when the script arrives with the page, and for as long as the script is late when it is not (304 milliseconds for a script held back 300, 1,519 for one held back 1,500). It is not hidden in advance on purpose: a visitor whose browser blocks scripts would otherwise never get a button. And the visitor’s own clock decides, so a device with the wrong time gets the wrong answer. Neither stops a button from working, and both are the price of working with a cache.

What a person’s line says

For a team, each person can have their own hours. Outside them the line is hidden, or it stays and says Back at 09:00, or, when that is not today, Back Tue 09:00. The checker above shows that line too. This is part of Beckonbird Pro; the pricing page has the details, and team lines the rest.