Yes. In a controlled experiment by Charity Navigator and Maastricht University, attendees who added GivingTuesday to their calendar via AddEvent showed a 45% lift in actual giving behavior compared to a control group that received no calendar intervention - matching the performance of a direct "give now" appeal.

The research behind it

The study tested four strategies across 65,000+ donor contacts ahead of GivingTuesday 2025:

• A hard pledge form (commit to an amount in advance)
• An Add to Calendar invitation via AddEvent
• A "give now" early donation appeal
• A holdout control group (no outreach)

Result: the Add to Calendar group and the "give now" group both achieved a 45% lift over control. The Add to Calendar approach outperformed the hard pledge by 25%.

Other documented results

• BuddyIns (virtual events platform): 30% increase in virtual attendance rates after adding Add to Calendar to their registration flow
• Brad Bizjack (coaching programs): doubled live attendance after adopting subscription calendars and Add to Calendar for his program schedule
• Achievers: 5% lift in event attendance and significant internal process savings after implementing AddEvent across their events team

Why it works

The core mechanism is what behavioral scientists call the intention-action gap. People register for events with strong intent, but that intent decays over time as competing priorities emerge. An event on a calendar:

• Creates a visible, daily reminder of the commitment
• Fires automatic device alerts at the right moment
• Competes actively with other scheduled items - rather than sitting passively in an inbox

Getting registrants to add your event to their calendar immediately at the point of registration is the single most reliable intervention for closing the gap between "signed up" and "showed up."