The date for remembering Matt Talbot appears to vary between June 18 and June 19, depending on the source. For example, the website at http://www.queenofpeace.ca/#Saint%20of%20the%20Day and the "Saint of the Day" at the Franciscan website, http://www.americancatholic.org/Features/saintofday/, both list June 18, 2008 for Matt Talbot. Last year, however, the latter website listed Matt Talbot on June 19, 2007 rather than June 18. Other websites that also list Matt for June 19 include the blog
http://whitewave39.blogspot.com/2007/08/ven-matthew-talbot-1856-1925-feastday.html, the Secular Franciscan Order at http://www.franciscan-sfo.org/p1/saintsp.htm, and the Secular Franciscan site at http://www.sfofraternities.org/56130/Saints.html
Also regarding dates, the Vatican's traditional day of choice when designating the feast day of a person beatified or canonized is the day of the person's death. Perhaps when Matt is so recognized, June 7 will be his suggested feast day.