How to Count Business Days (Without Missing a Deadline)

“Within 5 business days” is one of the most common phrases in contracts, banking, and shipping — and one of the most commonly miscounted. Here is the counting method used by institutions, with the edge cases spelled out.

The core rule

A business day is a weekday: Monday through Friday. To count N business days from a date, start at that date as day zero, move forward one calendar day at a time, and only count days that are weekdays. The N-th counted weekday is your answer. Two consequences follow:

Today never counts. If a bank says “funds available in 1 business day” on Monday, that means Tuesday — not Monday afternoon.
Weekends stretch the calendar. 5 business days from a Monday is the next Monday (7 calendar days). 5 business days from a Wednesday is the next Wednesday — still 7 calendar days. But 5 business days from a Friday is also the next Friday. The business-day count is stable; the calendar span depends on where the weekends fall.

What about public holidays?

Institutions skip the holidays they observe. A US bank skips the ~11 federal holidays; a UK court skips bank holidays; a courier may follow the holiday schedule of every country a parcel passes through. Since there is no universal list, general-purpose calculators (including ours) skip weekends only and tell you to subtract local holidays yourself: for each holiday inside your span, push the end date one weekday later.

Cut-off times: the hidden trap

Most banks and carriers have a daily cut-off, often between 2pm and 5pm local time. Anything submitted after cut-off is treated as if it arrived the next business day. If you wire money at 6pm Friday, the clock may not start until Monday — so “1–2 business days” can mean Wednesday. When a deadline matters, treat the cut-off as end of the previous day.

Counting backwards

Notice periods often run backwards: “notify us at least 10 business days before the renewal date.” The same rule applies in reverse — count weekdays backwards, holidays excluded. When in doubt, land your action one full business day earlier than the deadline requires.

Quick reference

1 business day from Friday → Monday
3 business days from Thursday → Tuesday
5 business days from any weekday → same weekday next week
10 business days ≈ 2 calendar weeks
20 business days ≈ 4 calendar weeks (a “working month”)

For an exact date, use the business days from today calculator — it does the weekday walk for any span up to 90 business days.