Measurement details
- Upstream reference
- Selected source
- Computer clock difference
- Fastest round trip
-
Request to complete response, including server processing. This
is delay, not clock error.
- Sample variation
-
Standard deviation of sample offsets before rejection.
Consistency does not establish UTC accuracy.
- Reference samples
- Time-source checks
- Drift allowance
- Timestamp resolution
- Visible-tick scheduling
- Frame cadence near the tick
The network range assumes a stable source clock and includes
timestamp resolution. It excludes unknown server error relative to
UTC. The drift allowance is a model, not a measured hardware
guarantee.
Callback measurements stop before the screen displays the pixels.
Screen refresh and display latency add delay that this website
cannot measure.
The page corrects its own display; it cannot change your system
clock. Use your operating system’s automatic date and time
settings to correct that clock, then check again.
