What commonalities or coincidences are there between the dates February 17 of 1790 & 1809 (include 1043 if +).?

ISO research assistantship in regards to perfect archival research on this sort of thing. This particular question draws from a sequence in 'pure mathematics' I call the '2-3-4 sequence'. The one that I closed a file on was 2171446447117 and the succeeding one was 2171809710439 (If anyone with contacts can advise on which members of the sequence these are, because of my approach to programming, I could use the info and will be slow in obtaining it possibly).