Deadline Calculator
Calculate a business-time deadline
Add business days or business hours to a start date and time. Weekends are skipped by default, and you can optionally use working hours for a more realistic deadline.
Deadline Calculator for business days and business hours
A lot of deadlines are set the wrong way: someone adds “3 days” to a date and forgets that weekends, working hours, and holidays exist. The result is a deadline that looks tidy on paper but fails in practice. This Deadline Calculator is built for one specific decision: if you start on a given date and time, when is the realistic deadline after a certain number of business days or business hours?
By default, the calculator assumes you are counting in business time, not calendar time. That means it can skip weekends (Monday to Friday only) and it can optionally apply working hours. If you choose “Business days,” the calculator moves forward by whole working days and keeps the same time-of-day. If you choose “Business hours,” it adds hours only inside the working window (for example 09:00 to 17:00), rolling over to the next working day when needed.
Use the quick inputs if you just need a fast answer. If you want a more realistic output, open the Advanced section and set your workday start and end times, plus any holiday dates you want excluded. The result shows the calculated deadline and a couple of supporting figures so you can sanity-check the output and communicate it clearly.
Assumptions and how to use this calculator
- If you leave the start date or start time blank, the calculator uses your current local date and time.
- When “Exclude weekends” is enabled, Saturdays and Sundays are treated as non-working days and are skipped in the countdown.
- When using “Business hours,” hours only count inside the workday window you enter (default is 09:00 to 17:00 if you leave it blank).
- Holiday dates are optional; if provided, each listed date is treated as a non-working day (it is skipped like a weekend day).
- This calculator is for deadline timing, not time zone conversion or meeting scheduling; it assumes one local time zone for start and deadline.
Common questions
What is the difference between business days and business hours?
Business days move in whole days, typically Monday to Friday, and ignore the number of working hours inside each day. Business hours count only the time inside your working window, so the deadline shifts based on your start time and the length of a workday.
If I start outside working hours, what happens?
If you choose business hours and your start time is before the workday starts or after it ends, the calculator begins counting from the next valid working moment (for example, the next workday start time). This prevents a misleading deadline that assumes work happens overnight.
How do holidays affect the result?
If you enter holiday dates, those dates are treated as non-working days. That means a deadline that would have landed on a holiday gets pushed forward to the next working day or working hour slot, depending on your unit selection.
Why does my deadline land on the same clock time when using business days?
That is the intended behavior for business-day counting. If you add 5 business days to a start of 10:30, the simplest common rule is “same time, later working day.” If you need a deadline tied to a fixed end-of-day time, use business hours with an end time, or adjust your start time to your cut-off time before calculating.
When should I not use this calculator?
Do not use it for time zone problems, global teams, or meeting planning. Also avoid using it when your “working time” is irregular (shift work, rotating schedules) unless you are comfortable approximating with a single workday window and a short holiday list.
