Calculate days between dates or add/subtract days
Days Until
30days
Or
4 weeks, 2 days
Or
0y 1m 2d
Time Breakdown
Inputs
Result
From January 1 to March 15, 2025 is 73 calendar days. That equals 10 weeks and 3 remaining days (73 / 7 = 10 remainder 3), or 0 years, 2 months, and 14 days.
Inputs
Result
Starting from January 1, 2025, adding 45 days: 31 remaining days in January + 14 days into February = February 15, 2025, which falls on a Saturday.
Enter start and end dates. The calculator shows difference in days, weeks, months, and years. It handles leap years, varying month lengths, and can include or exclude the end date. Example: Jan 1 to Dec 31 = 364 days.
| From | To | Calendar Days | Business Days (~) |
|---|---|---|---|
| Jan 1 | Jan 31 | 30 days | 22 days |
| Jan 1 | Dec 31 | 364 days | ~260 days |
| Jan 1, 2024 | Jan 1, 2025 | 366 days | ~262 days |
Enter a start date and number of days. Positive adds, negative subtracts. The calculator handles month/year boundaries automatically. Example: March 25 + 10 days = April 4.
| Start Date | Add Days | Result Date |
|---|---|---|
| March 25, 2024 | +10 | April 4, 2024 |
| Feb 20, 2024 | +10 | March 1, 2024 (leap year) |
| Dec 25, 2024 | +14 | January 8, 2025 |
| May 15, 2024 | -30 | April 15, 2024 |
A business day is Monday through Friday, excluding federal holidays. "5 business days" from Friday = next Friday (skipping weekend). Business day calculations are used for shipping, legal deadlines, and banking.
| Calendar Days | Approximate Business Days | Notes |
|---|---|---|
| 7 days | 5 days | One week |
| 14 days | 10 days | Two weeks |
| 30 days | ~21-22 days | About one month |
| 90 days | ~63-65 days | About 3 months |
Divide total days by 7. 21 days = 3 weeks. 45 days = 6 weeks 3 days. For partial weeks, the calculator shows the remainder. Useful for: Pregnancy (40 weeks), projects, term durations.
30 days: April, June, September, November. 31 days: January, March, May, July, August, October, December. 28 days: February (29 in leap years). Rhyme: "30 days has September, April, June, and November..."
| Month | Days | Cumulative Days in Year |
|---|---|---|
| January | 31 | 31 |
| February | 28/29 | 59/60 |
| March | 31 | 90/91 |
| April | 30 | 120/121 |
| June | 30 | 181/182 |
| December | 31 | 365/366 |
A year with 366 days (Feb 29). Occurs every 4 years, EXCEPT century years unless divisible by 400. 2024: Leap year. 2025-2027: Not. 2028: Leap year. 2100: NOT (century rule). 2000: Was leap year (÷400).
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Last Updated: Feb 12, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.