Federal holidays are the easy part. They're the same 11 days everywhere, and every business-day calculator handles them. State holidays are where it gets messy, because a day that's a normal workday in Texas might be a paid day off in Massachusetts — and if your team spans states, your business-day count has to account for all of them.

I learned this the hard way coordinating a rollout between our Boston and Salt Lake City offices. Boston shut down for Patriots' Day. Salt Lake shut down for Pioneer Day. Neither showed up in the federal calendar, and our shared deadline slipped twice before we figured out why.

The State Holidays That Actually Move Counts

Most states observe the 11 federal holidays and add a handful of their own. The ones most likely to affect your business-day count:

  • Patriots' Day (3rd Monday in April) — Massachusetts, Maine, Wisconsin, Connecticut. State offices and many schools close.
  • Pioneer Day (July 24) — Utah. Statewide closure, and most private employers follow.
  • César Chávez Day (March 31) — California, Texas, Arizona (observed by state agencies; private-sector coverage varies).
  • Juneteenth (June 19) — now federal, but state observation rules still vary for paid leave.
  • Indigenous Peoples' Day / Columbus Day — some states close, some don't, which creates inconsistent counts in October.
  • Lincoln's Birthday (February 12) — still observed by a few states including Illinois and Connecticut.

Whose Calendar Are You Counting On?

Here's the question that matters: whose workday are you actually counting? If a contract says "delivery in 10 business days" and your vendor is in Utah, Pioneer Day stops the clock for them. If your client is in California and you're billing by the business day, César Chávez Day may or may not count depending on their HR policy. The safe move is to ask which calendar applies before you commit to a date.

For internal planning, use the most restrictive calendar on your team. If anyone in the chain is off, the work doesn't move that day. It's better to over-count exclusions and deliver early than to under-count and miss.

Adding State Holidays to Your Calculator

Default business-day tools won't know about state holidays — they only see the federal list. You need a calculator that lets you pin extra dates. The Custom Exclude Calculator does exactly this: enter your date range or day count, then add the specific state holidays as custom exclusions. The tool strips weekends and federal holidays on its own, then removes your state-specific days on top.

If your team spans multiple states, build one exclusion list per state and use the union of all of them. That way a holiday in any one location pauses the count for the whole project.