Working days & holidays
Workday Calculator
Find a date a set number of working days before or after another date — excluding weekends and your own custom holidays. Calendar units are also available.
How this calculator works
Choose an anchor date, a direction (add or subtract), a whole-number amount, and a unit. Working-day units (working days, working weeks — the default) skip weekends and any custom holiday dates you add below; calendar units (days, weeks, months, years) are also available for a plain date shift with no exclusions.
Add your own bank or site holiday dates below; they apply to working-day units and to the working-day adjustment. There is no built-in country or regional holiday database, since holiday calendars depend on jurisdiction, region and year — you enter exactly the dates that matter for your calculation.
An optional adjustment can move the result to the nearest previous or next working day if it lands on a weekend or one of your custom holidays. The page always shows the raw calculated date alongside the adjusted one when they differ.
Calendar months and years preserve the day of month when possible. When the target month is too short — for example adding one month to 31 January — the result moves to that month's final valid day instead of overflowing into the next month.
Custom holidays are kept only in this page's memory for your current visit — nothing is saved, sent anywhere, or available on a future visit.
The tool is arithmetic only. Where legal, payroll, holiday, timezone or jurisdiction-specific rules matter, the page states what is and is not included.
Frequently asked questions
What's the difference between this and the Date Calculator?
This page's focus is working-day offsets — excluding weekends and your own custom holidays, with an optional working-day adjustment. The Date Calculator instead only adds or subtracts whole calendar days with no exclusions; use it when you specifically want plain calendar-day math. Calendar weeks, months and years are also available here as a secondary option.
What's the difference between this and the Business Days Calculator?
The Business Days Calculator counts how many weekdays fall between two dates you already have. This page instead finds the resulting date a set number of working (or calendar) days before or after one anchor date.
Does this know my country's public holidays?
No. There is no automatic country or regional holiday database. Add the specific bank or site holiday dates that matter for your calculation, and they'll be excluded from working-day units and the working-day adjustment.
What happens if I add a weekend date as a holiday?
It's labeled as already excluded and has no additional effect — weekends are always excluded from working-day units regardless of the custom holiday list, so a weekend holiday can never remove an extra working day.
Is this validated for clinical trial or regulatory scheduling?
No. This is a general-purpose arithmetic tool, not a protocol-compliant or clinically validated scheduling system. It performs the date math you configure and nothing more — verify results against your own protocol or institutional requirements. If you need a full multi-visit schedule with asymmetric early/late windows, see the Clinical Trial Visit Window Calculator.
Are my custom holidays saved for next time?
No. Nothing is stored anywhere — closing or reloading the page clears the list.