Date Calculator
Add or subtract days, weeks, months, years. Calculate exact difference duration between two dates with business day count option.
Date Calculator
Result
What is Date Calculator?
Date Calculator is a flexible date arithmetic tool for performing two common date-related operations calculating the exact difference between two dates and adding or subtracting a duration from a starting date. Project planning billing cycles subscription renewals contract expiration personal milestones all depend on accurate date calculations yet many developers do these manually counting on calendars or error-prone mental math. This calculator supports full calendar operations compute years months weeks days hours minutes seconds between two dates with breakdown across multiple granularities add or subtract any combination of years months weeks days hours minutes seconds from any starting date and critically supports configurable business day calculations excluding weekends Saturday Sunday and optional custom holiday lists for workday-only calculations important for SLA response time tracking payroll periods and project delivery estimates. Additional features include day-of-week display showing what weekday any date falls on quarter calculations financial Q1-Q4 boundaries ISO 8601 week numbering support and support for different regional calendar conventions. Handle edge cases like leap years correctly month-end dates adding 1 month to January 31 correctly handles February short months and varying month lengths automatically. All calculations use the browser built-in Date library with timezone awareness.
When to Use Date Calculator
Use when calculating project deadlines, SLA response windows, subscription renewal dates, age calculations, workday counts excluding holidays, contract expiration tracking, or determining billing cycle periods.
How to Use Date Calculator
Choose mode either difference between two dates or add/subtract duration from a date. Enter values and configure options including business day exclusions and holidays. Results show detailed breakdown across multiple units.
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