The Delaware GIS Day event is a great example of collaboration among different organizations to celebrate and educate about the value that GIS brings to education and society. The Delaware event will be held on Wednesday, November 14, 2018 at the Air Command Mobility Museum in Dover. Approximately 300 students plus the general public attend this event from around the state, traveling through 18 stations to learn how GIS is used in different industries. There is even an enormous Earth balloon! The content of these stations is tied to the 5th grade state curriculum. Delaware Geographic Data Committee partners with several organizations to host this event. They have even created a wonderfully detailed story map, here.
For more information, see the event website: http://www.mygeoworld.org/delaware-gis-day-2018/
If you are looking for ideas for your own GIS Day event, I invite you to examine the plans that Delaware has, and be encouraged and inspired!

The first section of the wonderfully detailed Delaware GIS Day story map.