Software Freedom Day is a global grassroots marketing campaign in which volunteers from around the world are invited to participate. From their website:

Software Freedom Day (SFD) is a worldwide celebration of Free and OpenSource Software (FOSS). Our goal in this celebration is to educate the worldwide public about of the benefits of using high quality FOSS in education, in government, at home, and in business — in short, everywhere! The non-profit company Software Freedom International provides guidance in organizing SFD, but volunteer teams around the world organize their own SFD events to impact their own communities.

There are many Software Freedom Day celebrations in New Zealand:

WLUG holds an annual SFD event: