Use this calendar tool when the calendar system, inclusivity rules, time zone, recurrence convention, and holiday inputs are explicit.

Start date

Required string. Inclusive lower bound of the range as a YYYY-MM-DD date.

End date

Required string. Inclusive upper bound of the range as a YYYY-MM-DD date.

Holidays

Optional list. Holiday dates (YYYY-MM-DD) subtracted when they fall on a weekday inside the range.

The cited overview of Calendar date supplies background for the terminology and domain context used by this tool.^[1]

Count weekdays Monday through Friday in an inclusive date range, optionally subtracting supplied holidays. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Business days (days)

Returned integer in days. Weekdays in the range after holiday subtraction.

Weekend days (days)

Returned integer in days. Saturday and Sunday occurrences in the range.

Holidays applied

Returned integer. Distinct holidays that fell on a weekday inside the range.

Total days (days)

Returned integer in days. Calendar days covered by the inclusive range.

• Civil calendars, holidays, daylight-saving transitions, month-end clamping, and jurisdiction-specific business-day rules can produce different valid interpretations.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

Store unambiguous ISO dates and zone identifiers, and verify official calendars or a standards-compliant scheduling library for operational use.

• Business Days Between

  Count weekdays in a half-open date range, optionally subtracting supplied holidays.

• Date Difference Calculator

  Calculate the signed number of calendar days between two ISO dates.

• Age Calculator

  Compute completed years, months, and days between a birth date and a reference date.