Tiny tools for everyday date math

Business Days Calculator

Calculate business days between two dates. Optionally exclude weekends (default) and your own holidays. We count days inclusive of start and end.

Holidays are treated as non‑business days. We count days inclusive of start and end.
› How this is calculated
We iterate calendar dates from start to end (inclusive) at local noon to avoid DST edge cases. A date counts if it's not a weekend (when excluded) and not in your holiday set. If start > end, we swap for convenience.

Examples

  • Payroll planning: From 2025‑09‑01 to 2025‑09‑30 excluding weekends and US holidays.
  • Project SOW: Contract signed 2025‑10‑03, delivery in 30 business days — use “Copy shareable link”.
  • Leave tracking: Count paid days off over a period by listing holidays.

FAQ

Is the count inclusive?
Yes—both the start and end dates are included when they qualify as business days.
How do holidays work?
Each line in the holidays box is treated as a non‑business day. We accept MM/DD/YYYY or YYYY‑MM‑DD.
Why do you use noon internally?
Using local noon avoids daylight‑saving transitions that can shift a date at midnight.