Tag Archives: time

10,000 Days Old Today!

I don’t know why I started keeping track of my age in number of days, but I’m willing to bet it was in anticipation of this very day. I’ve not tracked it for long though. Just a couple of months really.

If you’re curious when you’ll turn or you turned 10k days old, it comes around when we’re 27 years, 4 months and 16 days old. 20k days is, naturally, when we’re 54 years and 8 months which feels much more further away than it should. What does that tell us about time?

The day itself is pretty ordinary. I’ll get myself a little cake to celebrate, but I’d have probably done that in any case. It is raining the whole day today. Not sure what’s up with that. I wanted to go to Conrad to get a USB-A to USB-B cable, and just window shop, but doesn’t look like I’ll be doing that given the weather situation.

I don’t have much to write about here. Just wanted to make this milestone post. Having said that, I’ll link to some of my poorly written past articles talking about time below.

My birthdays

Turning 20 – Birthday Week

Turning 24 – Twenty-four

Turning 27 – Twenty-seven 🎂

My blog’s birthdays

1st anniversary of blog

4th anniversary of blog

6th anniversary of blog

Year reviews

2015 year review

2018 year review

2019 year review


4/8 Engineer

6/8 Engineer

7/8 Engineer

8/8 Engineer


Time and measuring time precisely with C++

When will we become engineers?

Be easy on yourself

The best time of your life is right now

In closing

Thank you for reading!

Let’s talk about Radio Clocks

After arriving in Berlin in January of 2019, I treated myself to a Casio F-91W. It was my first (non-essential) purchase in Germany, and for less than 10 Euros, it was a steal. Plus, a colleague of mine wore it and it looked cool. Easy decision!

Little did I know that this watch had a cult following on the internet. People collected all versions and variants of it and wore it with pride. I got pulled into the hype surrounding the F-91W and eventually more of the Casio retro digital watches.

It was an easy “hobby” to pursue given it is basically just buying more stuff. Nevertheless, it isn’t all that bad given how cheap these retro watches are. It is all relative of course, but given I’m also into photography, acquiring Casio watches is easier on my wallet.

Today, I own a couple more and I’m low-key proud of my collection.

Learning about Radio Clocks

Like with anything I get obsessed with, I spent a lot of time reading and watching YouTube videos about Casios. At some point I stumbled upon the Casio Wave-Ceptor series of watches. It struck me as something different: This fairly low tech wrist watch could set and correct its time automatically!

“But wait, it isn’t a smart watch” I thought. How does it do that?

That sent me down the rabbit hole which I’m still on my way down right now. Turns out, the watch can receive signals transmitted by a time signal transmitter and correct its local time.

In Germany, there’s Mainflingen longwave transmitter transmitting DCF77 time signal. The carrier signal has a 77.5 kHz frequency and the time signal is generated from the local atomic clock which syncs with the main atomic clock in Braunschweig. It is operated by the Physikalisch-Technische Bundesanstalt which also hosts four public NTP servers:





Querying the time using the commandline utility sntp and watching the network activity in Wireshark gives us some interesting data.


What’s next?

I’ve ordered a cheap radio receiver to play around with the radio time signal. On the watch side, I’ll look for cheap used radio Casio watches on the local Ebay here and try to acquire. I hope this new obsession ends up teaching me a thing or three about analog signals.

That is it for this side-quest post. Thank you for reading!