Standard Time
Standard time (UTC)
Your clock vs. the server
Measuring…
The time comes from this site's server (NTP-synced). The server reports whole seconds, so the page sends requests in quick succession and catches the moment the second changes to narrow the error down. A slow or lopsided connection (a long way out, a short way back) widens the error, which is shown above. This only measures this site's server; browsers cannot read other sites' server time.
Alarm
Alarms ring on the hour in UTC, or the chosen minutes before it. Your browser only allows sound after you press the button, and the tab must stay open.
About this tool
What does this tool show?
The current standard time to the millisecond, taken from this site's NTP-synced server, and how far your computer's or phone's clock is from it.
How accurate is it?
On a normal internet connection, within a few tens of milliseconds. It catches the moment the server's second changes to narrow the error down, and shows the remaining error range. A slow connection, or one that is much faster in one direction than the other, makes the error larger.
Can it show another website's server time?
No. Browsers cannot read other sites' server time, so it only measures this site's server.
How do the alarms work?
They ring on the hour, or 1 to 3 minutes before it, in the time zone of the big clock. Press the sound button once to allow sound, and keep the tab open for the alarm to ring.