About Clockzilla
Clockzilla is a precision time observatory that synchronizes with multiple atomic clock-referenced servers to deliver the most accurate time possible directly in your browser.
Unlike your computer's built-in clock, which can drift by seconds or even minutes over time, Clockzilla uses a multi-tier NTP-style synchronization engine that cross-references multiple time sources and applies statistical filtering to determine the true time with millisecond-level precision.
Our sync engine queries up to 3 independent time sources across multiple rounds, discards statistical outliers, and computes a weighted average that favors the lowest-latency, highest-accuracy samples. The result is a reliable offset measurement that tells you exactly how far ahead or behind your computer clock is.
Clockzilla also serves as a comprehensive world time reference, with current local time, timezone information, DST schedules, and sunrise/sunset times for over 150,000 cities worldwide. Whether you're scheduling an international meeting, tracking a distant event, or just curious what time it is somewhere, Clockzilla is built to be your daily time companion.
Features
Our Mission
We believe accurate time should be universally accessible, fast, and free. No sign-ups, no paywalls, no dark patterns. Clockzilla is a labor of love built for everyone who cares about knowing exactly what time it really is.