Federal
The federal calendar
Filing and payment deadlines by tax year, recomputed from the statutory rules each build.
Tax year
2026
32 deadlines, January 15, 2026 to December 15, 2026.
Tax year
2027
32 deadlines, January 15, 2027 to December 15, 2027.
How the dates are produced
Each date is computed from its rule in IRS Publication 509 rather than stored as a fixed date, then shifted to the next business day if it lands on a weekend or a federal holiday. Federal holidays are computed for the specific year per 5 U.S.C. 6103. April also accounts for DC Emancipation Day, which is why the individual filing deadline is sometimes later than April 15.