TL;DR: There are so many days in a year that have some special significance, it felt worth having a compilation of all of those that are relevant for us!
Epistemic Status: It was laborious (even with Claude) to gather and curate this list, and there are probably many more days worth mentioning that were not on the lists I went through! Also, part of the value is in cutting out some days to really make it a selection, but I may have removed things that should have been on this list! Feel free to comment so I update the post :)
Organizing a local group for about a year, I noticed that maybe half of the workload is coming up with themes for the events. The other half is picking a date that works with both enough of the organizers, and enough members of our group.
And yet, my impression is that the periods our group has seen the most growth is when we unilaterally decided to take random themes, and pick dates arbitrarily. The single most important factor being: announcing the event soon enough for people to book the date.
So here's your cheatsheet: all the 68 next events your group should run :)
| Date | Special day |
|---|---|
| Jan 14 | World Logic Day (UNESCO) |
| Jan 24 | International Day of Education |
| Jan 26 | International Day of Clean Energy |
| Jan 28 | International Day of Peaceful Coexistence |
| Feb 4 | International Day of Human Fraternity |
| Feb 8 | Benjamin Lay Day |
| Feb 10 | World Pulses Day |
| Feb 11 | Women & Girls in Science Day (UN) |
| Feb 12 | Darwin Day |
| Mar 3 | World Wildlife Day (UN) |
| Mar 5 | International Day for Disarmament and Non-Proliferation Awareness |
| Mar 8 | International Women’s Day |
| Mar 20 | International Day of Happiness |
| Mar 22 | World Water Day (UN) |
| Mar 24 | World Tuberculosis Day |
| Apr 5 | International Day of Conscience |
| Apr 7 | World Health Day (WHO) |
| Apr 22 | Earth Day |
| Apr 24 | World immunization week |
| Apr 25 | World Malaria Day (WHO) |
| May 15 | International Day of Plant Health |
| May 16 | International Day of Living Together in Peace |
| May 21 | World Day for Cultural Diversity for Dialogue and Development |
| May 22 | Biodiversity Day (UN) |
| May 23 | International Day to End Obstetric Fistula |
| Jun 5 | World Environment Day (UN) |
| Jun 6 | World Food Safety Day |
| Jun 8 | World Oceans Day (UN) |
| Jun 10 | International Day for Dialogue among Civilizations |
| Jun 14 | World Blood Donor Day |
| Jun 17 | World Day to Combat Desertification and Drought |
| Jun 19 | International Day for the Elimination of Sexual Violence in Conflict |
| Jun 21 | Summer Solstice |
| Jun 23 | Turing Day |
| Jul 11 | World Population Day (UN) |
| Jul 12 | International Day of Hope |
| Jul 20 | International Moon Day |
| Jul 25 | World Drowning Prevention Day |
| Jul 28 | World Hepatitis Day |
| Aug 29 | Day Against Nuclear Tests (UN) |
| Sep 5 | International Day of Charity (UN) |
| Sep 7 | International Day of Clean Air for Blue Skies (UNEP) |
| Sep 8 | International Literacy Day (UNESCO) |
| Sep 15 | International Day of Democracy |
| Sep 21 | International Day of Peace (UN) |
| Sep 26 | Petrov Day |
| Oct 2 | World Day for Farmed Animals |
| Oct 4 | World Animal Day |
| Oct 10 | World Mental Health Day (WHO) |
| Oct 13 | International Day for Disaster Risk Reduction |
| Oct 16 | World Food Day (UN) |
| Oct 17 | Day for Eradication of Poverty (UN) |
| Oct 24 | World Development Information Day |
| Oct 29 | International Day of Care and Support |
| Nov 1 | World Vegan Day |
| Nov 4 | Joseph Rotblat Day |
| Nov 10 | World Science Day for Peace and Development (UNESCO) |
| Nov (mid) | World Antibiotic Awareness Week |
| Nov 21 | World Philosophy Day (UNESCO) |
| Nov 25 | World Day for the Elimination of Violence against Women |
| Nov (Tue after US Thanksgiving) | Giving Tuesday |
| Dec 1 | World AIDS Day |
| Dec 5 | World Volunteer Day |
| Dec 10 | Human Rights Day (UN) |
| Dec 10 | International Animal Rights Day |
| Dec 20 | International Human Solidarity Day |
| Dec 27 | International Day of Epidemic Preparedness |
| Dec 31 | Well, you know :) |
Hope you'll find some use for it! And I wish you a happy... What day is it today?

I think of today (February 8) as "Benjamin Lay Day", for what it's worth. (Funny timing :) .)
Another one I'd personally add might be November 4 for Joseph Rotblat. And just in case you haven't seen / just for reference, there are some related resources on the Forum, e.g. here https://forum.effectivealtruism.org/topics/events-on-the-ea-forum, and here https://forum.effectivealtruism.org/posts/QFfWmPPEKXrh6gZa3/the-ea-holiday-calendar .
In fact I think the Forum team may also still maintain a list/calendar of possible days to celebrate somewhere. ( @Dane Valerie might know?)