What Is Date:Italy?

It’s actually worse than that. It wasn’t always whole coubtries who decided to adopt (or not) but cities and sometimes people within cities (i.e. the protestants in the city would be lagging, or maybe I’m misremembering and this was about people who where abroad)

In any case, for awhile, the date you picked depended on who you were writing to. And then also the relative standing. If he was of much lower standing you might force your own calendar on them.

Also, I think with the previous calendar it was always a bit debatable what year december belonged to. I can’t quite remember the details.

Julian date is sometimes used to synchronize timing for encrypted radio systems. My understanding is that early radio systems adapted it because it was used by astronomers. Astronomers used it because it didn't skip any days which would cause issues tracking long term astronomical cycles.

Good write up! Relevant folklore Usenet post about the history of the calendar I am again obligated to share: https://neosmart.net/forums/threads/an-extended-history-of-t...

I wonder how Paradox handles this stuff in their games like Europa Universalis. Have they ever made a "the pope wants you to switch calendar systems" event which changes the actual in-game date?

Please use HTTPS.

I use HTTPS only. I don't think HTTP is acceptable for anyone let alone a technical blog post. It takes a few minutes, and it prevents me and all your visitors from getting all kinds of MITM injections.

Thanks.