This piece is cross-posted on TechPresident where I post articles on the intersection of politics, technology and transparency and serve as an editor.

Three years ago, after a chance encounter with Daniela Silva and Pedro Markun of Sao Paulo and a meeting with Edward Ocampo-Gooding and Mary Beth Baker in Ottawa, with whom I shared a passion about open data, we agreed to simultaneously host events in our three cities on the same day. It would be a hackathon, and because it would take place in at least two countries … we liberally called it “international” inviting others to join us.

In that first year we had about six cities conduct events on every continent save Australia. Now in its third year, Open Data Day events is far bigger than we ever dared imagine. More interesting still is its impact, both expected and unexpected.

Reflecting on it all, I thought it might be worthwhile to share a little bit about the impact I think Open Data has, and some lessons hacktvists may find interesting to draw upon.

Build Community

From the beginning our goal was simple. It wasn’t code, or even opening data per se. It was about community.

We wanted to foster a friendly event where anyone would feel welcome to participate. The team in Ottawa had, in particular, done great work in reaching out an engaging new people in previous hackathons, they’d have a wealth of non-software developers and even full families attend their events. This was as much a hackathon as it was a community event.

So Open Data Day was always meant to serve as a catalyst for community and network creation. Yes, creating, adding to or working on a project was strongly encouraged, but the real output to help open data advocates find and connect with one another, as well as grow the movement by engaging new people. An effective community was always going to be the core ingredient for petitioning a government to make data open, teaching students or policy makers how to use data or have a group of developers launch a project. While we wanted to create cool software, visualizations and analysis, what I wanted even more was to foster local leaders, champions, social glue and community hubs.

And that’s what we got.

One of the strengths of Open Data Day is its incredible decentralized nature. I blog about it to encourage people to organize and help moderate a mailing list, but beyond that everything is done by local volunteers. From a capacity building perspective, it is an incredible event to watch unfold. I’d like to think Open Data Day has played a helpful role in connecting local stakeholders and even knitting them together with regional, national and international peers.

While I believe that a beautiful piece of code can be critical in making policy makers, the public or others see the world in a different light I also think that building community and developing allies who can share that story of that code with leaders and the public at large is, depending on the breadth of your goals, equally important.

What Works for Communities Can Work for Governments

Almost immediately upon launch of Open Data Day, government officials began showing up at the hackathons. Some came unofficially, others officially, and in some places, the hackathons were invited to take place at city hall. Because we set a venue Open Data Day created a predictable publicized space where governments that were curious, reluctant, eager or cautious could come and engage at a speed that worked for them.

When you build a safe place for a broader community – if your event has more of the feel of a public consultation or community meet-up than a gathering of subversive technologists – you can create space for governments. More importantly, the one thing that characterizes most open data hackathons I’ve witnessed or investigated,is that the participants share a desire to make their community better. That is something most government officials can easily wrap their heads around.

Thus, in a way that I don’t think anyone planned, Open Data Day events have become a place where governments want to understand more of what is possible, learn about the community that is interested in data and wrestle with how open data can change the way they work. What began with a few pioneering cities three years ago has evolved where now places like the Victoria Palace in Romania (the seat of government) and the White House in Washington DC are hosting Open Data Day events.

This type of engagement creates new opportunities, and new challenges, but that is exactly the type of progress many movements would like to see.

Plant a Flag

Setting a date and having people around the world step up and embrace had another interesting impact. It created a deadline not just for community organizers who were organizing their local open data day event, but also for governments that want to engage these communities.

Indeed in the past it has been amazing to see how many governments now see Open Data Day as a deadline for launching open data portals or releasing additional data sets. This is a fantastic outcome as it creates subtle pressure on governments to act.

This year was no exception. I heard of governments around the world releasing data sets in anticipation of Open Data Day. In particular there was a flurry of activity from European governments and agencies. Indeed the European Union chose to launch its open data portal in time for Open Data Day. But there was also much activity across the continent. This included that launch of data portals for the Building Performance Institute Europe, the Italian Senate, the city of Venice , the city ofTrento, the region of Puglia in the south of Italy, and the province of Bolzano. But the practice has become widespread. I was particularly happy to see a city a few kilometers from my home town do the same: the City of Victoria, BC launched its Open Data portal for the day.

These announcements show the amplifying effect of getting organized across geographies. The advocacy work of a group in one country helps reinforce a message that benefits advocates in other countries. This is pretty basic stuff — political advocacy 101 if you will — but it is a reminder of why congregating around a single date, and meeting in person still have value for those who are unpersuaded.

Ultimately Open Data Day is important because it serves the needs of local advocates and activists wherever they are. That means keeping the event coherent so that it can continue to be a global event that people understand, yet flexible so that it can satisfy local needs and desires. For example, the event in Manila focused on poverty while in Washington DC it focused on building community and capacity. These types of events are not, in of themselves, going to completely solve a problem, but I do believe that they are part of a broader political effort that activates a community, engages government and creates pressure for change.