It is very simple. The USHPA has declared that May 29th will be
National Hang Gliding and Paragliding Day.

What you, or your club, or your business, or your region or your association of
any kind does with this is totally up to you.

Some activities:

The Midwest hang
gliding competition. They will be flying a task that day.

The Texas Single Surface Shootout (still waiting for sanctioning) will be flying
a task that day.

Write in and announce what you will be up to that day.