Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
Business Days Calculator
Count the number of working days between two dates, or add/subtract business days to/from a date. Exclude weekends and optionally add holidays.
Business Days Calculator
Excluded Holidays (weekends are always excluded)
Select dates to calculate business days
- Choose a mode — "Count Between Dates" to calculate business days in a range, or "Add / Subtract" to find a date after/before a given number of business days.
- Select dates — Pick start and end dates (or start date + business days count).
- Add holidays — Optionally add specific dates to exclude (e.g., public holidays, company off-days).
- View results — See the total business days, calendar days, weekend days, and holiday breakdown.
What counts as a business day?
Business days are Monday through Friday, excluding weekends (Saturday and Sunday). You can also add custom holidays that fall on weekdays to exclude them, such as public holidays or company-specific days off.
Does this account for regional holidays?
No. This calculator does not include a built-in holiday calendar. You must manually add any holidays you want to exclude. This gives you full control to account for your specific region, country, or company holidays.
How does the Add/Subtract mode work?
It calculates a date that is N business days before or after a given date. It skips weekends and any added holidays, counting only Monday-Friday working days. For example, 5 business days after Monday is the following Monday (skipping one weekend).
Does it count the start date?
In "Count Between Dates" mode, both the start and end dates are included in the count. In "Add / Subtract" mode, the start date is not counted — the calculation adds or subtracts the specified number of business days from the start date.
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