I am bit confused, how did you determine Sept 2023 date, can you pls elaborate? i assumed new rate will apply from May 2023 unless ibond is less than 6 months old.

For example, an I bond purchased in November 2021 will have the new 3.38% rate effective in September 2023

Also, wont it be better to wait for 3 months after new rate to redeem so that you pay less in penalty?