Usage patterns
先日は〈事〉をありがとうございましたthank you for ~ the other day
Thank you for the celebration the other day.
先日〈場所〉で〈人〉に会ったran into/met someone somewhere the other day
I ran into Tanaka at the station the other day.
先日お話しした〈事〉the matter we discussed the other day
I'm contacting you about the matter we discussed the other day.