The official iRacing schedules match up reasonably well with my proposed track list this season
It never works out 100% though so some events may be a week before or after the iRacing race.
You can consider this pretty much final.
Star MazdaWeek 1 Sebring International
Week 3 Brands Hatch GP
Week 5 Infineon IRL
Week 7 Zandvoort GP
Week 9 VIR Full
Week 11 Watkins Glen Boot
Riley Daytona Prototype Week 2
Brands Hatch GP Silverstone GP
Week 4 Sebring International
Week 6 Watkins Glen Boot
Week 8 Road America Full
Week 10 Infineon Long
Week 12
Silverstone GP Brands Hatch GP