Hi,
I was wondering is there a designated date when people around the world celebrate Bitcoin invention or creation of cryptocurrencies in general? I mean commonly accepted tradition, something like
International Programmers' Day:
Programmers are greeted with positive comments like Happy Programmers Day in some work environments on International Programmers' Day. The observance is also mentioned among programming communities in online forums and social media, including on Facebook or Twitter.
I think it would be fun to have such a day for the crypto community

That is very hard to do since bitcoin is decentralized. Organized groups who have a center agencies can make such programs and activities. In order for bitcoin to have such approved program and activities there must be an organization enlisted so they can propose a bitcoin day. There are legalities to be considered and I guess it is hard to do that except if we will make a consensus.