Date Difference
Quick presets
Add / Subtract from a Date
Business / Working Days
Weekends (Sat & Sun) are excluded. Indian public holidays are not automatically excluded.
Select two dates to see the result
Difference
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Breakdown
Result will appear here
How Date Difference is Calculated
Total Days
(Date₂ − Date₁) ÷ 86400000
86400000 ms = 1 day
Total Weeks
Total Days ÷ 7
Remainder = extra days
Business Days
Exclude Sat + Sun
Iterate day by day
Example Calculations
Days between India's Republic Day and Independence Day
Start26 Jan 2026
End15 Aug 2026
Days200 days
Weeks28 weeks, 4 days
Add 90 days to a date
Start01 Apr 2026
Add90 days
Result30 Jun 2026
Day of weekTuesday
Frequently Asked Questions
How do I calculate the number of days between two dates?
Enter the start date and end date in the Date Difference tab above. The calculator instantly shows total days, weeks, months, and years between the two dates.
How do I add days to a date?
Use the Add/Subtract tab. Enter your start date, select "Add", enter the number of days (or weeks, months, years), and the result date appears instantly.
What are business days?
Business days (working days) are Monday through Friday, excluding Saturday and Sunday. This is commonly used for contract deadlines, financial settlement, and notice periods. Indian public holidays are not automatically excluded.
How many weeks are in a year?
A standard year has 52 weeks and 1 day (365 days). A leap year has 52 weeks and 2 days (366 days). Our calculator shows exact weeks and remaining days between any two dates.
How is the date difference formula calculated?
Both dates are converted to milliseconds since the Unix epoch (1 Jan 1970). The absolute difference is divided by 86,400,000 (ms in a day) to get total days. Weeks, months, and years are derived from this.