The grassroots team coordinating the March for Science in Washington, D.C., have now set a date: 22 April. And they are inviting organizers in cities around the world to lead parallel demonstrations.

Organizers have said they want to appeal to anyone who, as its mission statement puts it, “champions publicly funded and publicly communicated science as a pillar of human freedom and prosperity.” Organizers have emphasized that the march is not just for practicing scientists, but for “anyone who believes in empirical science.”

The event, at first just an idea bouncing around social media, gained real life last month after a website, Twitter account, and public Facebook page—now with more than 300,000 likes—sprang up over the course of a few days. An affiliated “secret” Facebook group attracted almost 800,000 members in less than a week, and more than 70 Twitter handles have popped up to promote sister marches across the country.

Scientists began organizing only 3 days after President Donald Trump took office, as alarm—sparked by a campaign that in many ways appeared to dismiss the contributions of scientific research—ignited over Senate hearings on controversial cabinet picks and mandates curtailing public communication from scientific agencies. Many scientists took the administration’s promotion of “alternative facts” and continued shunning of scientific leaders as signs that science may come under attack.

It’s not the first time that Trump’s actions have triggered activism among scientists, a group that, as a whole, has traditionally couched itself as nonpartisan. At the December 2016 meeting of the American Geophysical Union in San Francisco, California, researchers rallied together to protest climate change doubters among Trump’s cabinet picks. And at the Women’s March on Washington, dozens of lab coat–clad scientists marched together, armed with pro-science signs.

But the march has spurred debate about how its message should be framed—and whether it is even a good idea. Some fear a demonstration led by researchers might only serve to paint scientists as an interest group, further politicizing scientific issues. And at least one veteran science lobbyist has urged organizers to make sure it’s a march for science, not scientists.

The march organizers—an eclectic mix of researchers and science communicators who came together online—were unprepared for how quickly the march gained support, scrambling to draft a mission statement, appoint a team, and set an official march date over the weekend. On their Facebook group and in an email to Science Insider, organizers repeatedly asked for patience as they strove to get their “messaging, action items, and announcement right the first time.”

Although the less-than-rapid progress triggered some impatience among followers, many others posted their support, suggesting it wouldn’t truly be a scientist’s march if the process wasn’t somewhat slow and deliberate.

“We scientists certainly understand that only 10 [percent] of what we do is worthy of public discussion. Plod on,” wrote retired chemist Tim Clair, in one of hundreds of Facebook comments responding to the team’s promises that information would be coming soon.

March organizers are expected to release more details in coming days.