Online time: see the current time and check that it is right
Online time means the current time shown in a web page. The AlarmPick online clock shows the time and date of your device as a digital clock with seconds, or as a clock face with hands. This guide shows how to use it and how to check that the time it shows is right.
The short answer
- Open the online clock. The large numbers are the local time of your device.
- Read the seconds and the date shown under the time.
- Choose 12-hour or 24-hour time. The choice stays in your browser.
- To check the time, compare your device with an official source such as time.gov.
The one rule that matters: the page repeats your device clock. If your device is wrong, the page is wrong too.
Where the time on an online clock comes from
AlarmPick Clock reads the time and date already set on your computer or phone. It does not ask a time server. It also has no time source of its own, so it is not an atomic clock.
This is why two sites can show different seconds. Time.gov, for example, says its clocks are corrected for network delay. A page that reads your device, like this one, shows what your device believes.
How to check your clock against official time
The US site time.gov is labelled "Official U.S. Time". It says its clocks are corrected for network delay. It also has a "Your Device's Clock" readout and a "Your clock is off by:" field, so you can see how far your device differs.
- Open time.gov in one tab and the AlarmPick clock in another.
- Read the "Your clock is off by:" value on time.gov.
- If the gap matters to you, turn on automatic time in your device settings.
UTC, and why zones differ by offsets
Clocks around the world are tied to Coordinated Universal Time. NIST says UTC "is based on International Atomic Time (TAI), but it is adjusted by leap seconds". It also says UTC is "the standard used for all general timekeeping applications".
Leap seconds exist to keep UTC close to Earth's rotation. NIST says their purpose is to keep UTC "within ±0.9 s of the UT1 astronomical time scale". It gives the current difference between UTC and TAI as 37 seconds, with TAI ahead.
Your local time is UTC plus an offset for your zone. The IANA Time Zone Database holds "code and data that represent the history of local time for many representative locations worldwide". It is updated when political bodies change zone rules, and most people receive those updates through their software and operating system.
Why the time on your screen may be wrong
- The time zone setting is wrong. The usual cause when the clock is off by whole hours.
- Automatic time is off, so the device clock has drifted.
- The device missed a software update after a zone rule changed.
A gap of whole hours points to the zone. A gap of seconds or minutes points to drift.
Digital, analog and 12-hour or 24-hour time
| View | What you see | Good for |
|---|---|---|
| Digital | Large numbers, seconds and the date | Reading the exact second |
| Analog | A face with hands, same device time | A glance across a room |
| 12-hour | AM or PM shown | Everyday reading in many countries |
| 24-hour | 00:00 to 23:59 | Timetables and schedules |
Worked example: 15:45 in 24-hour time is 3:45 PM. Subtract 12 from 15 to get 3. Midnight, 00:00, is 12:00 AM.
How to use the AlarmPick clock
- Open the online clock.
- Read the large time. The seconds and today's date are part of the display.
- Press 12-hour or 24-hour. The choice is saved on this device and used the next time you open the page.
- Switch to the clock face with hands if you prefer it.
- Press Full screen to enlarge the clock when your browser allows it.
- Press Dim screen to darken the page. It does not change the brightness of your device.
The page also shows the time zone name the browser provides. That name describes the browser setting, not your physical location.
Limits to know about
- Closing the browser stops the clock.
- A hidden tab may draw less often. When you return, the page reads the device clock again.
- The page does not count down to a time you choose. For that, use the online timer, or set an online alarm for a clock time.
- For the time in other cities, use the world clock.
Frequently asked questions
Is an online clock the same as official time?
No. An online clock that reads your device shows your device time. Official time comes from a standards lab, such as the source behind time.gov.
Why does my online clock differ from another site by a few seconds?
One of the two clocks is off by a few seconds. The cause may be your device, or the other site.
Does the clock show seconds?
Yes. The digital view shows seconds and the date.
Does the clock keep running in a background tab?
The page keeps no count of its own. A hidden tab may draw less often, and the page reads your device clock again when you return.
Does the page need an account?
No. It is free to use, and the format choice stays only in your browser.