Posters are due every year on April 1.
Projects are due ever year on April 1 (Grades 4-6 and 7-9) and May 30 (Grades 10-12).

Again this year, the ASA/NCTM Joint Committee on the Curriculum in Statistics and Probability and the American Statistical Association's Center for Statistics Education encourage students and their advisors to participate in its annual Poster Competition and Project Competition. Committees of distinguished statisticians and dedicated teachers of statistics meet each year to evaluate entries.

A statistical project is the process of answering a research question using statistical techniques and presenting the work in a written report.

A statistical poster is a display containing two or more related graphics that summarize a set of data, look at the data from different points of view, and answer specific questions about the data.

https://www.amstat.org/education/posterprojects/index.cfm