About the service

Each departure records the instant it began counting and how much was left at that instant. What's left now is a subtraction from the device's clock, never a count of intervals.

So a departure stays right with the page in the background, the device asleep or the browser closed: on return, the board shows the right time and records the exact moment the departure left.

Departures, lines and the stopwatch are kept on this device alone, in the browser's storage. Nothing is sent to the Terminal: no account, no tracking, no ads.

Several open tabs show the same board. Clearing the browser's data clears the board.

After the first visit, Epoch works without the internet. From the browser's menu, use Install app or Add to Home Screen to keep it as an app.

With the page in the background, browsers delay alerts to save battery: time stays right, but the chime and the notification may come late. On iPhone and iPad, notifications need the app installed on the Home Screen.

For alerts that can't fail, keep the platform open: the screen stays on while it's in view.