Calculate exact intervals, working business days, and future date offsets.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Select Date Difference or Add/Subtract Time.
Select your starting and ending date/time values.
Inspect total days, business days, hours, and full ISO 8601 formatting.
The calculator excludes Saturdays and Sundays between the start and end dates.
Zero-egress companion tools in the Date & Time suite
Convert times across world timezones and compute exact business days.
Convert between Unix timestamps and human-readable UTC/ISO dates.
Calculate calendar and custom fiscal year quarters starting in any month (e.g. Feb, July, Oct).
Convert clock in/out minutes to standard payroll decimal hours (15-min / 6-min increments).
