I was looking to apply to Harvard REA and Caltech EA. (I know you can’t do both)
I searched the website but did not find any information regarding the deadlines for the letters of recommendation to submitted.
Is the deadline same as the application, that is November 1st?
Harvard’s website says Nov 1 is deadline for all application materials on this page in the timeline section: https://college.harvard.edu/admissions/apply/first-year-applicants
On a quick look at CalTech’s site the deadline for various application components does not seem to be addressed so you have two choices: get everything in by the EA deadline, or reach out to admissions and ask if there is a window of opportunity to send in any application components after the deadline.
Good luck.
They won’t read yourapp on the day you submit it. But whenever they do, you want solid recs in place. Remember how quickly they turn around decisions for Early apps.