It makes no sense that TurboTax's text says January 1, 2026, because for the purpose of suggesting estimated tax payments for 2026 what matters is your age on December 31, 2026. This is probably one of the many inappropriate wording changes that TurboTax has made as it is being migrated to a new implementation of the step-by-step mode user interface. They seem to be changing wording just for the sake of changing the wording, without regard to the reason behind the original wording.
