# A PTP Wall Clock is impractical and a little too precise

> Source: <https://www.jeffgeerling.com/blog/2026/ptp-wall-clock-impractical-too-precise/>
> Published: 2026-03-06 15:00:00+00:00

After seeing Oliver Ettlin's 39C3 presentation Excuse me, what precise time is It?, I wanted to replicate the PTP (Precision Time Protocol) clock he used live to demonstrate PTP clock sync:
I pinged him on LinkedIn inquiring about the build (I wasn't the only one!), and shortly thereafter, he published Gemini2350/ptp-wallclock, a repository with rough instructions for the build, and his C++ application to display PTP time (if available on the network) on a set of two LED matrix displays, using a Raspberry Pi.