For the past few months, people have been asking me about these two clocks that keep showing up in my videos—one in my rack, another at my desk.
Both are PoE-powered NTP clocks from a local company called Masterclock 
In that second picture is my 'Time Pi', a project I've been working on for over a year which runs a Raspberry Pi as a Stratum 1 NTP/PTP server with a timing-specific GPS module from u-blox. More details on my blog: https://www.jeffgeerling.com/blog/2025/diy-ptp-grandmaster-clock-raspberry-pi
I was honored to be visited by John Clark (Masterclock's CEO) and Dr. Demetrios Matsakis, former Chief Scientist at the US Naval Observatory, a physicist who contributed much to our understanding of time (and it's measurement). We spoke at length about DIY timing solutions!
The result of those many months of work is this first video in a series on time and timekeeping with a Raspberry Pi time server (called 'Time Pi'), and that video is out this morning! Watch it here: https://www.youtube.com/watch?v=zT71UvUxhjU
@geerlingguy your pun game is on point lately. Funny and clever… every time.
@geerlingguy This is cool. Computer timing across machines is one of those rabbit holes that seemingly goes forever. Like how so many companies just deemed the cost of leap seconds and flip flopping on the every 100 years except when every 400 years thing as not worth solving.
@geerlingguy yay! I’ve been so looking forward to more of your time stuff 
@geerlingguy
To prove worthy of the name please post an image of a clock showing 03:14:15
@geerlingguy thanks for yet another, very insightful and entertaining video! Also I really like the outfit, really suits you. Now I know who needs to star as the next Doctor in #DoctorWho or in a #BackToTheFuture sequel :-). 
@geerlingguy btw. regarding time/timing I'm wondering if this accurate timing, maybe together with the new Linux realtime kernel changes, could be useful to implement MIMO beamforming with multiple Raspberry Pis. So that multiple Pis transmit the same thing and adjust a delay to focus the transmission onto a specific receiver. I guess for Wifi this would still not be precise enough, but maybe for something with a slower encoding, @meshtastic maybe, it might?
@T_X @meshtastic for mesh, it would probably bring more benefit to just use a directional antenna for that purpose (most of us just use an omnidirectional stick!). But could be fun.
@geerlingguy What an honour 