The deadline for filing the Foreign Bank and Financial Accounts (FBAR) form, also known as FinCEN Form 114, is April 15th of the following calendar year. However, there is an automatic extension available until October 15th if needed.
This means that the deadline for filing FBAR is typically the same as the deadline for filing individual income tax returns in the United States. It is important to note that if April 15th falls on a weekend or holiday, the FBAR deadline is adjusted accordingly, and the new deadline would be the next business day.
Find more about FBAR here: FBAR: Requirements, Deadlines, and How to File