Date Calculator
Add or subtract days, weeks, months, or years from any date.
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How It Works
Calculates the difference between two dates in days, weeks, months, or years. Enter a target date to see how many days until (or since) that date from today.
Formula
New Date = Start +/- DaysQuick Reference
Common calculations — results you can verify instantly.
Jan 1 to Jul 4
183 days apart
~6 months
Mar 15 to Dec 31
Days until year end
~291 days
30 days from today
Add 30 days
Next month approx
Tips & Shortcuts
Working days calculation: total days minus weekends (and holidays if needed).
Due dates: add days to today to find deadlines.
Age in days: everyone has lived different days even if same birth year.
Common Mistakes
Forgetting leap years in long-range calculations
February has 29 days in leap years (divisible by 4, except centuries not divisible by 400).
Confusing calendar months with 30-day months
Months have 28-31 days. For precise calculations, use day counts rather than month arithmetic.
Frequently Asked Questions
183 days (184 in a leap year). Use the calculator for precise counts.
Enter your birth date to find the day of the week automatically.
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