correct day for R Dev Day @ posit::conf

Author: hturner

events/r-dev-days/index.md

@@ -24,7 +24,7 @@ details will be linked here as they become available.
 | [Rencontres R 2025 (19-21 May)](https://pretix.eu/r-contributors/r-dev-day-rr2025/) | Mons, Belgium    | Thurs 22 May  | Confirmed |
 | useR! 2025 (8-10 Aug)         | Durham, NC, USA  | Mon 11 Aug    | Tentative |
 | RSECon25 (9-11 Sep)           | Warwick, UK      | Fri 12 Sep    | Tentative |
-| posit::conf (16-18 Sep)       | Atlanta, GA, USA | Thu 19 Sep    | Tentative |
+| posit::conf (16-18 Sep)       | Atlanta, GA, USA | Fri 19 Sep    | Tentative |
 | [Shiny in Production (8-9 Oct)](https://pretix.eu/r-contributors/r-dev-day-sip-2025/) | Newcastle, UK    | 7-8 Oct       | Confirmed |
 
 ## What happens at an R Dev Day?