GPS/PPS clock
Time, from my Raspberry Pi.
I built a Stratum 1 time server at home. These clocks use its GPS/PPS time when connected, displayed in your timezone, mine, and UTC.
Your time
--:--:--.---
UTC ·
Leo's time
--:--:--.---
Asia/Shanghai · UTC+08:00
UTC
--:--:--.---
UTC+00:00
Source: Your Device Clock (Fallback)
- Round-trip latency
- Not synchronized
- Estimated correction to your device clock
- Not synchronized
- Last synchronization
- Not synchronized
- Synchronization interval
- Every 60 seconds while this tab is visible
A positive correction means the Pi clock was ahead of your device at synchronization. This is an estimate, limited by network delay.
Where the time comes from
My Raspberry Pi gets time from a GPS receiver and its pulse-per-second signal. It also serves NTP to my home network. This page reads that same disciplined system clock through a small time API.
01
GPS → Raspberry Pi
GPS and PPS discipline the Pi clock. The API checks that PPS is selected, Stratum 1 is reported, and synchronization is healthy.
02
Pi → Cloudflare
A protected tunnel carries fresh timestamps to the website. The browser never receives the service credentials.
03
Cloudflare → Your browser
Three samples estimate the time correction. The browser advances that clock locally between synchronizations.
Milliseconds, with context
The digits show milliseconds, but they do not promise millisecond accuracy. I subtract the Pi's processing time from the round trip and estimate the return journey as half the remaining delay. Unequal travel times still introduce error.
If the request fails, times out, or reports an unhealthy clock, every display immediately uses Your Device Clock (Fallback). Your timezone comes from your browser settings; it does not decide the synchronized time.