Easily convert between days, months, and years. Enter a number and see the equivalent in days, months, years, weeks, and hours. Perfect for travel planning, project scheduling, contract period calculations, and more.
Enter the number you want to convert in the input field. Decimal values are also accepted.
Select the input unit from the dropdown: Days, Months, or Years.
Click the 'Convert' button to instantly see the equivalent values in days, months, years, weeks, and hours.
Date unit conversion is incredibly useful when planning international trips, business travel, study abroad programs, or working holidays. For example, you can quickly determine how many months a 90-day visa-free period covers, or exactly how many days a 6-month language course lasts. It is also convenient for converting lease contract durations to days when staying abroad long-term, or for back-calculating your return date from a given number of days.
When creating schedules for software development, construction, research, or any other project, converting between time units is a frequent necessity. You can instantly check how many weeks a 3-month project spans, or how many years and months a 500-day project equals. This tool is especially helpful when building Gantt charts, setting milestones, and estimating labor hours by converting project days to hours for cost calculation purposes.
Understanding exact time periods is crucial in lease agreements, employment contracts, and insurance policies. You can quickly calculate how many days a 2-year contract covers, or how many months a 180-day warranty period represents. In legal disputes where precise period calculation matters, having an accurate day-count conversion is essential, and this tool provides error-free calculations for such scenarios.
This calculator uses 365.25 days per year, which accounts for leap years (366 days) that occur every 4 years. The actual Gregorian calendar averages 365.2425 days per year, but 365.25 provides sufficient accuracy for general conversions. For exact date-to-date calculations, consider using a calendar-based date calculator alongside this tool.
One month is calculated as approximately 30.4375 days (365.25 / 12). While actual months range from 28 to 31 days, this average value provides more accurate results for long-term period conversions. For short-term calculations involving specific months, keep in mind that February has 28 or 29 days, and months alternate between 30 and 31 days.
Decimal input is fully supported, so you can convert precise periods like '1.5 years' or '2.5 months'. This is particularly useful for fine-tuning project timelines or calculating partial contract periods with precision.
The 'Weeks' result is based on calendar weeks (7 days each), not business weeks (5 working days). If you need the number of business weeks, divide the days result by 5 instead. This distinction is important for project planning and resource allocation.
The 'Hours' result is calculated using 24 hours per day. If you need business hours (typically 8 hours per working day), multiply the days result by 8 instead. This is especially useful for estimating project labor hours, calculating freelance billing, or planning study schedules.
The Earth takes approximately 365.2422 days to orbit the Sun. To compensate for this, a leap year (366 days) occurs every 4 years, making the average year length 365.25 days. This average is used for accurate period conversion. While the Gregorian calendar has additional rules (skipping leap years every 100 years, except every 400 years), resulting in an average of 365.2425 days, 365.25 provides sufficient accuracy for general unit conversion purposes.
This converter provides average-based period conversions. Since actual months vary between 28 and 31 days, there may be slight differences compared to exact calendar calculations. For example, converting '3 months' gives approximately 91.3 days, but from January 1st, three calendar months later (April 1st) is exactly 90 days (91 in a leap year). For precise date-to-date calculations, we recommend using a dedicated date calculator alongside this converter.
Decimals represent the fractional portion of the unit. For example, '2.50 months' means 2 months and half a month (approximately 15 days). Similarly, '1.25 years' equals 1 year and 3 months (0.25 x 12 = 3 months). For exact day counts, refer to the 'Days' result. Note that the actual calendar date corresponding to a decimal value depends on the starting date.
This converter uses calendar days for all calculations. For working-day conversions, multiply the days result by 5/7 to get an approximate number of working days. For example, 365 calendar days equals approximately 260.7 working days. However, this does not account for public holidays, so for precise working-day calculations, consider using a dedicated business day calculator that includes holiday data for your region.
Yes, this converter uses JavaScript floating-point arithmetic and can handle very large numbers. However, extremely large values (e.g., billions of years) may experience minor rounding errors due to floating-point precision limits. For typical ranges (within thousands of years), the results are perfectly accurate. Large result values automatically include thousand separators (commas) for easy readability.
Hours are a frequently needed unit in project labor estimation, cost calculation, and study time planning. For example, knowing that a 30-day project equals 720 hours (30 x 24) helps you break it down into work hours (e.g., 8 hours/day x working days) for staffing plans. It is also useful for converting online course durations or certification training hours into day equivalents for scheduling purposes.
Converting between date units is a surprisingly common need in both daily life and professional settings. When planning a trip, you might wonder how many months 90 days is. When reviewing a contract, you need to know exactly how many days 24 months covers. When scheduling a project, figuring out how many years and months 500 days equals becomes essential. In international business environments, expressing durations in various units is frequently required. This date unit converter is designed to handle bidirectional conversion between days, months, and years, while also providing additional results in weeks and hours for maximum versatility. The conversion is based on astronomical averages: one year is set to 365.25 days (approximating the Earth's orbital period of 365.2422 days), and one month is 365.25 divided by 12, yielding approximately 30.4375 days. These average-based conversions ensure high accuracy for long-term period calculations across diverse applications.
Date unit conversion plays a critical role across numerous professional fields. In human resources management, probation periods (typically 3 or 6 months) are converted to days to determine exact end dates, and years of service are tracked for leave entitlement calculations. In real estate, lease durations (usually 1-2 years) are converted to days for pro-rata calculations, or exact lease expiry dates are determined. The insurance industry requires converting coverage periods, exclusion periods, and reduction periods between various units. In software development, sprint durations (typically 2-4 weeks) are converted to days, and overall project timelines are reported in months or quarters. Education also relies heavily on period conversion, with semesters (4-5 months), academic years (about 10 months), and vacation periods (about 2 months) frequently converted to days or weeks. Date unit conversion is truly a fundamental tool used across virtually every industry.
There are several important caveats to keep in mind when converting date units. First, since this converter uses average values, results may differ from exact calendar-day counts between specific dates. For instance, 3 months from January equals 90 calendar days, but the average conversion yields about 91.3 days. For legally precise period calculations, always use actual calendar dates. Second, the definition of a 'month' can vary by context. In legal settings, a month often refers to a calendar month, while in finance, 30 days may be used as a standard month. Third, be mindful of the difference between working days and calendar days. If you need project durations in working days, multiply the calendar days result by 5/7 and subtract applicable public holidays. For these specialized scenarios, consider using professional date calculation tools as complementary resources to ensure complete accuracy.