Date & Time Duration Calculator
Calculate time between dates and times with full precision. Our date and time calculator returns the duration as years, months, days, hours, and minutes — plus totals in each unit.
Date & Time Duration Calculator
Calculate exact duration between two dates and times — years, months, days, hours, and minutes
What Is a Date & Time Duration Calculator?
A date and time duration calculator computes the precise time interval between two moments — including both the calendar date and the time of day. Unlike a simple days counter, this tool accounts for hours and minutes, so durations like “3 days 14 hours 22 minutes” are fully supported.
This is the most comprehensive tool for calculating time between dates. It's ideal for project management (how long did Phase 1 take?), medical records (how long since a diagnosis?), legal timelines (how many days, hours since an incident?), and engineering (exactly how long did a process run?).
How to Calculate the Duration Between Two Dates
- 1Enter the start date and start time in the top section.
- 2Enter the end date and end time in the bottom section.
- 3Click "Calculate Duration" to compute the exact result.
- 4Read the headline breakdown: years, months, days, hours, minutes, seconds.
- 5Use the totals row for the result in a single unit (total days, total hours, total minutes).
- 6Click "Copy" to grab the full result as text.
Duration Between Two Dates — Examples
Frequently Asked Questions
How do I calculate the duration between two dates and times?
Enter your start date and time in the first section, then your end date and time in the second section. Click "Calculate Duration" to get the exact result broken down into years, months, days, hours, minutes, and seconds — plus totals in each unit.
What is the difference between this tool and the Days Between Dates calculator?
The Days Between Dates calculator only counts full calendar days. This Date & Time Duration Calculator includes the time component, so a span from 9 AM January 1 to 5 PM January 2 returns "1 day 8 hours" rather than just "1 day."
Can I calculate time between dates across months and years?
Yes. Enter any two dates and times regardless of how far apart they are. The tool accurately calculates years, months, and days by accounting for variable month lengths and leap years, plus provides the exact total in days, hours, and minutes.
How do I calculate the duration between a date in the past and today?
Set the start date to your past date and the end date to today's date. The tool calculates the exact duration elapsed since then, including the full breakdown down to seconds.
What is the formula for calculating time duration between two dates?
Convert both datetime values to a common unit (milliseconds since Unix epoch), subtract, then convert the difference back to years, months, days, hours, minutes, and seconds by working down from the largest unit. This tool handles all variable month lengths and leap years automatically.