Every result has a clear counting rule.

We use real calendar dates and show the assumptions that matter near each result.

Date difference

The difference excludes the start date and includes the end date. Monday to Tuesday is therefore one calendar day. Negative differences are presented as an absolute distance while the date order remains visible in the inputs.

Business days

A business day is Monday through Friday. Saturday and Sunday are skipped. Public, bank, regional, and company holidays are not removed because those calendars vary by location and organization.

Date addition

Days and weeks are added as elapsed calendar time. Month and year calculations use the browser's calendar handling, including leap years and the different lengths of months.

Exact age

Exact age is expressed as complete years, remaining complete months, and remaining days between the birth date and the comparison date.

Last reviewed: August 8, 2026