Calculate date differences instantly. Compute days, weeks, months, and years between two dates with detailed breakdown.
• Select start and end dates to calculate the difference
• Results show days, weeks, months, and years
• Detailed breakdown includes all time units
A date calculator computes the difference between two dates, showing the result in various time units (days, weeks, months, years). Whether you need to calculate project timelines, determine age, find days until an event, or compute billing periods, a date calculator provides instant, accurate results without manual counting or complex calculations.
Our free Date Calculator takes two dates and calculates the precise difference between them. It shows results in multiple formats: total days, weeks, months, and years, plus a detailed breakdown combining all units. Perfect for project planning, age calculations, event countdowns, subscription periods, and any scenario where you need to know the time between dates.
Calculating date differences manually is error-prone and time-consuming, especially when accounting for varying month lengths, leap years, and different calendar systems. A date calculator handles all these complexities automatically, providing accurate results instantly. It's essential for:
Days represent the total number of 24-hour periods between two dates. This is the most precise unit and forms the basis for all other calculations. The calculator counts each complete day, excluding partial days.
Weeks are calculated by dividing total days by 7. One week equals 7 days. Weeks are useful for project planning, work schedules, and recurring events.
Months are more complex because month lengths vary (28-31 days). Our calculator uses an average of 30.44 days per month (accounting for all 12 months). For precise month calculations, it also provides a detailed breakdown that accounts for actual month boundaries.
Years account for leap years, using 365.25 days per year on average. This ensures accurate calculations across leap year boundaries. The detailed breakdown shows exact years, months, weeks, and days remaining.
Date difference calculation involves:
The calculator uses precise conversion factors: 7 days per week, 30.44 days per month (average), and 365.25 days per year (accounting for leap years).
Note: Month and year calculations use averages for simplicity. For exact calculations considering actual month boundaries, the detailed breakdown provides more precision.
To calculate age: Enter birth date as start date and today as end date. The result shows exact age in years, months, weeks, and days.
For project timelines: Enter project start and end dates to see total duration in all time units, useful for planning and resource allocation.
For billing: Calculate subscription period from start to end date to determine billing cycles and renewal dates.
Our date calculator:
Month calculations use an average of 30.44 days per month. For exact month boundaries, use the detailed breakdown which shows years, months, weeks, and days separately.
Yes, year calculations use 365.25 days per year on average, which accounts for leap years occurring every 4 years.
Yes, you can enter any two dates, past or future. The calculator shows the absolute difference regardless of date order.
The calculator counts complete days only. Partial days (hours, minutes) are not included in the day count.
The calculator uses your browser's local time zone. Both dates are interpreted in local time.