Date Calculator

How to Use Enter two dates to calculate the difference in days, weeks, months, or years. Enter a start date and add or subtract N days to find the resulting date. Enter any date to see the D-day countdown from today. A business-days calculation excludes weekends. Who Is This For Anyone counting down to a deadline, trip, exam, or contract expiry date. Project managers tracking how many days remain until a milestone. Developers verifying date arithmetic logic before writing date-handling code. Key Features • Difference between two dates (days / weeks / months / years) • Add or subtract N days from a date • D-day countdown from today • Business days calculation (weekends excluded) • Leap year and month-end handling Frequently Asked Questions Q: Why can't I just add 30 days manually and get the right date? A: Months have 28–31 days, so simple arithmetic fails. This tool uses a proper calendar-based calculation. Q: Does the business days calculation include public holidays? A: By default, only weekends are excluded. Public holidays vary by country and must be accounted for manually. Q: How is 'age' calculated — is it complete years? A: Full calendar years are counted. The age increments on the birthday, not on January 1st. Tips In contracts, '30 days' typically means 30 calendar days unless explicitly stated as business days. Always confirm the counting convention when a legal deadline is involved. Use the D-day feature to stay aware of approaching contract renewals or subscription expirations.