Exact Time Now

How We Measure Your Clock

Why Clocks Drift

How Devices Sync Time

Popular time zones

Related tools

Frequently Asked Questions

What is the exact time right now?

The exact time is displayed at the top of this page, synchronized to within 100 milliseconds of Coordinated Universal Time (UTC). UTC is maintained by a worldwide network of atomic clocks and serves as the basis for all civil timekeeping.

How accurate is this page?

This page achieves accuracy within approximately 50–100 milliseconds of true UTC. We measure the round-trip time of multiple HTTP requests to calculate the network delay, then compute the offset between your device clock and the server's NTP-synced clock. The median of several samples is used to minimize jitter.

Why is my computer clock wrong?

Computer clocks use quartz crystal oscillators that drift by several seconds per week due to temperature changes and manufacturing tolerances. While operating systems synchronize periodically via NTP, the interval between syncs (often hours or days) allows drift to accumulate. Laptops in sleep mode can drift even more since sync is paused.

What is an atomic clock?

An atomic clock measures time by counting the microwave oscillations of caesium-133 atoms, which vibrate exactly 9,192,631,770 times per second. This frequency defines the SI second. Modern optical lattice clocks using strontium or ytterbium achieve accuracies of 10⁻¹⁸, meaning they would lose less than one second over the age of the universe.

What is NTP (Network Time Protocol)?

NTP (RFC 5905) is the standard protocol computers use to synchronize their clocks over a network. It uses a hierarchy of time sources called strata: Stratum 0 are atomic clocks and GPS receivers, Stratum 1 servers connect directly to them, and Stratum 2+ servers cascade from there. NTP can achieve accuracy within a few milliseconds on LANs and tens of milliseconds over the internet.

What is UTC?

Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time. It is maintained by the Bureau International des Poids et Mesures (BIPM) using data from over 450 atomic clocks in 80+ laboratories worldwide. UTC is within 0.9 seconds of UT1 (mean solar time) thanks to occasional leap seconds.