Date & Time
Calculator
Find the number of days between any two dates, count down to an upcoming event, or add and subtract days from any date. Includes business days, weeks, months, and years.
What counts as a business day?
Business days are Monday through Friday, excluding weekends. This calculator counts business days as all weekdays between two dates — it does not exclude federal holidays (which vary by country, state, and employer). If you need to exclude holidays, subtract them manually from the business days count shown above.
How months and years are approximated
Because months have different lengths (28–31 days), the "months" shown is total days divided by 30.44 (the average month length). Similarly, years uses 365.25 to account for leap years. For exact calendar month differences — e.g. "exactly 3 months and 14 days" — the result shows the breakdown in the full detail row.
Common uses for date calculations
Contract deadlines and notice periods (30, 60, 90 days). Pregnancy due dates and milestone tracking. Loan and lease term end dates. Subscription renewal planning. Court-ordered time periods. Project sprints and delivery schedules. Medication schedules. Legal statutes of limitations.
Leap years and date math
A leap year occurs every 4 years (when the year is divisible by 4), except for century years unless divisible by 400. 2024 was a leap year; 2100 will not be. This matters when calculating long date spans — a year-long period that includes Feb 29 has 366 days instead of 365. This calculator accounts for leap years automatically.
Calculate days between dates, add or subtract days from a date, and count business days.