Found this old thread and added the last couple years (can I count this as non-clinical volunteering)
2023: Friday Feb 24th (idk time)
2022: Saturday Feb 26th (idk time)
2021: Monday March 8th (idk time)
2020: Friday March 13th (decisions largely around 3:30 pm PST
“2019: Friday March 8 (First Acceptance at 3:03 PM)
2018: Thursday March 8 (First Acceptance at 3:21 PM)
2017: Thursday March 9 (First Acceptance at 1:32 PM)
2016: Wednesday February 24 (First Acceptance at 12:14)
2015: Thursday March 12 (First Acceptance at 10:31 AM)
2014: Thursday March 13 (First Acceptance at 10:13 AM)
2013: Monday March 11 (First Acceptance at 9:38 AM)
2012: Thursday March 15 (First Acceptance at 9:06 AM)
2011: Tuesday March 8 (First Acceptance at 9:51 AM)
2010: Wednesday March 3 (First Acceptance at 2:55 PM)
2009: Friday February 27 (First Acceptance at 11:22 AM)
2008: Friday March 7 (Can't find SDN Thread)”