Flip Clock

What it does

It shows the hours and minutes on four large cards, the way a split-flap clock does, in 24-hour or 12-hour time. Press Start — or Go Fullscreen — and each card that changes folds over at the turn of the minute: the top half falls, then the bottom half settles.

Before you press anything, it is still a working clock. The digits simply change with a short, soft fade instead of the flip, so the page never moves until you ask it to, and never shows you a wrong time while it waits.

Whose time is this?

Your device's. The page has no clock of its own and asks no server; it reads the time your operating system reports. If that is wrong, it is wrong here too, and fixing it in your system settings fixes it on this page.

Why there are no seconds

A flip every second is a great deal of movement for something meant to sit quietly on a shelf, and the charm of a flip clock is the minute turning over. Between those changes the clock rests entirely — nothing is redrawn — which also keeps it light on a laptop battery. If you want seconds, or the date, the Fullscreen Clock has both; for timing something, there is the Stopwatch.

Keeping the screen awake

Keep screen awake is off until you switch it on. A clock is exactly the kind of page people leave open for hours, and keeping a screen on costs power and, on an OLED panel, wear from the same bright shapes sitting in place. If you do switch it on, it is held only while the clock is running, released when you press Stop, hide the tab or leave, and the status line says whether your browser actually agreed.