Days in a Year Calculator
Find out how many days are in any year, check if it's a leap year, see the weekday breakdown, count remaining days, and calculate days between any two dates. Everything runs in your browser — private and instant.
Day of Week Breakdown
| Day | Count |
|---|
Days in Each Month
| Month | Days |
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Days Between Two Dates
Fun Facts
Quick Reference: Days in Each Month
| Month | Days (Common Year) | Days (Leap Year) |
|---|---|---|
| January | 31 | 31 |
| February | 28 | 29 |
| March | 31 | 31 |
| April | 30 | 30 |
| May | 31 | 31 |
| June | 30 | 30 |
| July | 31 | 31 |
| August | 31 | 31 |
| September | 30 | 30 |
| October | 31 | 31 |
| November | 30 | 30 |
| December | 31 | 31 |
| Total | 365 | 366 |
How Many Days Are in a Year?
A common year has exactly 365 days, while a leap year has 366 days. The extra day is added to February, giving it 29 days instead of the usual 28. This adjustment accounts for the fact that Earth's orbital period around the Sun is approximately 365.242199 days, not a clean 365. Without leap years, our calendar would drift by about 24 days every century, eventually shifting seasons out of alignment with calendar months. The Gregorian calendar, introduced in 1582, uses a precise leap year rule to keep the calendar synchronized with Earth's orbit to within one day every 3,236 years.
Understanding Leap Years
A year is a leap year if it is divisible by 4, with one exception: century years (divisible by 100) are NOT leap years unless they are also divisible by 400. This means 2000 was a leap year (divisible by 400), but 1900 was not (divisible by 100 but not 400). The next century leap year will be 2400. Under this system, there are 97 leap years in every 400-year cycle, making the average calendar year 365.2425 days long. This is remarkably close to the actual tropical year of 365.24219 days, resulting in an error of only about 26 seconds per year.
Weekdays vs Weekends in a Year
In a standard 365-day year, there are either 260 or 261 weekdays and 104 or 105 weekend days, depending on which day of the week the year starts. A year always has at least 52 full weeks (364 days), plus one extra day in a common year or two extra days in a leap year. These extra days determine whether certain days of the week appear 53 times rather than 52. For business planning and payroll, knowing the exact number of weekdays is essential. Many employers calculate salaries based on 260 working days (52 weeks times 5 days), but the actual count varies by year.
Days in Each Month
The twelve months of the Gregorian calendar have either 28, 30, or 31 days. Seven months have 31 days (January, March, May, July, August, October, December), four months have 30 days (April, June, September, November), and February has 28 or 29 days. A popular mnemonic is "Thirty days hath September, April, June, and November. All the rest have thirty-one, except February alone, which has twenty-eight days clear, and twenty-nine each leap year." This pattern has remained unchanged since the Julian calendar reform in 46 BC, though the leap year rule was refined with the Gregorian calendar.