Time & Date Calculator
Start Time
End Time
Start Time
Add Duration
Start Date
End Date
Start Date
Add Duration
Free Online Time and Date Calculator - Calculate Duration & Future Dates
This page has separate time and date modes. Use Difference to compare two clock times or calendar dates, and Add to move forward from a selected time or date. The results include a readable duration and totals that can help with a simple timesheet, a project milestone, or planning a future appointment.
Calendar calculations depend on the dates entered, including varying month lengths and leap years. A date difference measures the interval between the selected dates; it does not automatically include both endpoints. For arrangements affected by time zones, daylight-saving changes, contracts, or statutory deadlines, confirm the result against the relevant calendar or policy.
For a fuller explanation of how the breakdown is built and whether the first day counts, see How to Calculate Days Between Dates and Your Exact Age.
Time Difference Calculator
Calculate exact hours, minutes, and seconds between two times. Perfect for tracking work hours, billable time, or elapsed duration.
Date Difference Calculator
Find the difference between two dates in years, months, weeks, and days. Calculate age, project duration, or days until an event.
Add Time to Date
Calculate what date will be after adding specific days, weeks, months, or years. Plan deadlines and future events easily.
Add Duration to Time
Find out what time it will be after adding hours, minutes, or seconds. Great for scheduling and time zone conversions.
How to Use the Time & Date Calculator
- Choose Time Calculator or Date Calculator mode
- Select Difference to calculate between two values, or Add to calculate a future time/date
- Enter your values (start time/date and end time/date, or duration to add)
- Click Calculate to get instant results with detailed breakdown
Good to Know About the Results
- A date difference is the interval between the two dates; it does not automatically count both the first and last day.
- The breakdown follows the real calendar, accounting for leap years and months of different lengths.
- Adding to a date returns the resulting date along with its day of the week.
- Totals use averages. A "months" total relies on an average month length, so it can read as a decimal.
- Whole calendar days only. The date tools ignore time zones and daylight-saving shifts.
- More detail in How to Calculate Days Between Dates and Your Exact Age.
Common Use Cases
- How many days until my event? - Use date difference to count down to birthdays, weddings, holidays
- Calculate my age exactly - Enter your birthdate and today's date for precise age in years, months, days
- Track work hours - Calculate time spent on tasks for timesheets and billing
- Project deadline planning - Add weeks or months to start date to find end date
- Loan or contract duration - Calculate exact duration between two dates
Frequently Asked Questions
Yes. Age is a date difference between a birth date and an end date, so set the end date to today for a current age, or to a past or future date to see the age at that point.
The result measures the interval from the start date to the end date. If you need an inclusive count for a schedule, add one day after checking that this matches your convention.
Yes! Use the "Add Date" feature. Enter today's date and add 100 days to get the exact future date and day of week.
Yes. When you add time that exceeds 24 hours, it shows how many days ahead the result is.
The month and year totals are derived from the day count using average lengths, so they can include a fraction. For an exact calendar figure, read the years, months, and days breakdown instead.
About VioApps
This time, date, and age calculator is part of VioApps, a browser-based collection of everyday utility tools. It helps you compute date differences, plan around deadlines, and calculate age in years, months, and days without pulling out a phone calendar app.
Fast & Light
No downloads required
Secure
Your data stays private
Responsive
Works on all devices