Date & Time Extra
10 tools available. All calculations and file processing stay 100% private in your browser.
Convert 4
- Add ISO 8601 Duration to Date/TimeAdd standard ISO 8601 duration strings (e.g. P1Y2M10DT2H30M) to any base date-time with calendar arithmetic.
- Epoch Milliseconds to Nanoseconds ConverterConvert between 13-digit epoch milliseconds and 19-digit nanosecond timestamps bidirectionally using BigInt precision.
- Epoch Seconds to Milliseconds ConverterConvert between 10-digit epoch seconds and 13-digit epoch milliseconds bidirectionally with UTC verification.
- Week Number to Date Range Converter (ISO Week)Calculate the starting Monday and ending Sunday calendar dates for any given ISO 8601 week number and year.
Calculate & Analyze 3
- Business Days Calculator (Custom Public Holidays)Calculate working business days between two dates, excluding weekends and a custom user-provided list of public holidays.
- Quarter Start and End Date CalculatorFind the exact starting and ending calendar dates for any specified quarter (Q1, Q2, Q3, Q4) and year.
- Time Zone Difference & Offset CalculatorCalculate the exact hour and minute time difference and UTC offsets between two global timezones at any reference time.
Inspect & Extract 3
- Add/Subtract Business Days (Custom Holidays)Add or subtract working business days from a starting date, skipping weekends and custom public holidays.
- Monthly Days & Weekday Summary TableGenerate an annual breakdown table showing total days, working weekdays, and weekend days for every month of the year.
- Subtract ISO 8601 Duration from Date/TimeSubtract standard ISO 8601 duration strings (e.g. P1Y2M10DT2H30M) from any base date-time with calendar arithmetic.