Calculate days, weeks, months between two dates — or add and subtract days from any date
Date arithmetic is deceptively complex when done manually: calculating how many days until a project deadline, determining what date is 90 days from today for a payment term, finding out how many working days are between two dates, or checking when a six-month contract expires all require tracking month lengths, leap years, and calendar edge cases. This date calculator handles all standard date arithmetic: add or subtract any number of days, weeks, months, or years from a starting date; calculate the exact interval between two dates in multiple units simultaneously; and identify the day of the week for any date. Consider a freelancer who invoices clients on net-30 or net-60 terms and needs to instantly know the exact due date without miscounting across month boundaries. Or a human resources coordinator confirming that a new hire's 90-day probationary review falls on a Tuesday rather than a holiday weekend. A property manager renewing annual leases needs to know precisely what date is twelve months from a tenant's move-in day — not an approximation, but the exact calendar date accounting for leap years and varying month lengths. These are the kinds of date questions that seem simple at first glance but consistently trip up mental arithmetic. Project managers, legal professionals, accountants, and operations teams benefit most from having a reliable date tool at hand, since their workflows routinely hinge on exact dates and contractual intervals where a one-day error carries real consequences. All calculations run entirely in your browser, so no dates or personal scheduling details are ever sent to a server. Whether you are planning a product launch, tracking a warranty expiration, or scheduling recurring financial events, this calculator removes the guesswork from calendar math and delivers precise results in seconds.
Days between dates — Find the exact number of days, weeks, months, and years between any two calendar dates.
Date arithmetic — Add or subtract a number of days from a date to find a future or past date.
Weekday exclusion — Toggle 'exclude weekends' to count only business/working days between two dates.
Detailed breakdown — Result is shown in years, months, and days simultaneously for maximum clarity.