There are two different clocks on the board. The live clock at the top is a genuine, continuously-updating browser clock (it ticks every second from the device's own system time). The time-left countdown and the on-time/overdue colouring on each order card work differently: they compare the order's promised time (stored by the server in your business time zone) against a "now" value that the server only stamps into the page when it was last fully loaded — while the tab sits open, that reference does not keep tracking the device's live clock. Two things can make the countdown look off: (1) if the kitchen device's time zone doesn't match your business's time zone, the times and colours will be skewed by that offset, and (2) if the KDS tab has been left open a long time without a full page reload, the countdown can fall behind real elapsed time. Set the device to the correct time zone, and do a full page reload from time to time (not just leave the tab open) to keep the countdowns accurate.