Date Calculator
Calculate date differences, add or subtract days from dates, and find days between two dates. Perfect for planning deadlines, events, and countdowns.
Result
Result Date
Monday, February 16, 2026
Weekday
Monday
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Last updated: January 2026
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Frequently Asked Questions
How do I calculate the number of days between two dates?
To find days between dates, subtract the earlier date from the later date. For simple calculation: count the months between dates, multiply by the average days per month (30.44), then adjust for the specific days. For example, January 15 to March 20: 2 months + 5 days = about 64 days. For exact calculation, our tool counts every day including leap years. The difference between January 1, 2024 and December 31, 2024 is exactly 365 days (2024 is a leap year).
How do I add or subtract days from a specific date?
To add days, simply count forward from your starting date. To subtract, count backward. For manual calculation: add 30 for each month, then adjust. For example, adding 45 days to March 10: add 31 (rest of March) + 14 more days = April 24. Our calculator handles month lengths and leap years automatically. Adding 100 days to January 1 gives April 10 (or April 11 in leap years).
What is the difference between calendar days and business days?
Calendar days include every day—weekends and holidays. Business days (or working days) typically exclude weekends (Saturday and Sunday) and public holidays. For example, 14 calendar days = 10 business days (excluding 4 weekend days). When calculating deadlines, contracts often specify 'business days' for deliverables and 'calendar days' for payment terms. Our calculator can exclude weekends for accurate business day counting.
How do I find what day of the week a date falls on?
Each date has a specific day of the week based on the calendar system. For quick mental calculation, use the Doomsday algorithm: memorize that 4/4, 6/6, 8/8, 10/10, 12/12 all fall on the same day each year (the 'Doomsday'). Then count forward or back. For 2024, Doomsday is Thursday. So April 4, 2024 is Thursday, meaning April 1 is Monday. Our calculator shows the weekday instantly for any date.
How do I calculate weeks and months between dates?
For weeks: divide the total days by 7. For example, 45 days = 6 weeks and 3 days. For months: count complete months, then remaining days. This gets tricky because months have different lengths (28-31 days). From January 15 to April 15 is exactly 3 months. From January 31 to February 28/29 is technically 1 month, even though it's only 28-29 days. Our calculator provides accurate breakdowns in years, months, weeks, and days.