# Time Difference Calculator

URL: https://speedycalculator.com/calculators/everyday-life/time-difference/
Last updated: 2026-10-25

> The time difference calculator finds the exact time between two dates and times – optionally in different time zones – in days, hours and minutes, total hours, minutes and seconds.

## Inputs

- Start date
- Start time
- End date
- End time
- End time zone ahead of start by (h)

## Results

- Time difference
- Days
- and hours
- and minutes
- Total hours
- Total minutes
- Total seconds

## Formula

```
Difference = (end date + end time − zone offset) − (start date + start time)
Zone offset = how many hours the end time's zone is ahead of the start time's zone
```

## Explanation

Comparing times across time zones – for flights, calls or deadlines – means converting both to the same zone first. A flight leaving London at 10:00 and landing in New York at 13:00 the same day (5 hours behind) takes 8 hours.

### How to use the Time Difference Calculator

- **Start date**
- **Start time**
- **End date**
- **End time**
- **End time zone ahead of start by**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the start date and time, the end date and time, and – if they are in different time zones – how many hours the end zone is ahead (negative if behind).

### Tips

- Check whether the end date should be included – event durations usually include it, elapsed time does not.
- Months have 28–31 days, so "one month" is counted by calendar date, not as 30 days.
- Use 24-hour time or set AM/PM carefully when entering clock times.
- Time zones and daylight-saving changes are not applied unless the calculator says so.

### Common mistakes to avoid

- Counting a 30-day month when a calendar month is meant (or the reverse).
- Forgetting leap years when counting days across February.
- Mixing decimal hours (7.5 h) with clock time (7:30).

### Inputs explained

FieldWhat to enterStart dateA dateStart timeA clock time (hours and minutes)End dateA dateEnd timeA clock time (hours and minutes)End time zone ahead of start byIn h

### What each result means

- **Time difference** = [Difference in hours]
- **Days** = sign([Difference in hours])×floor(abs([Difference in hours])÷24)
- **and hours** = sign([Difference in hours])×floor(mod(abs([Difference in hours]), 24))
- **and minutes** = sign([Difference in hours])×round(mod(abs([Difference in hours])×60, 60))
- **Total hours** = [Difference in hours]
- **Total minutes** = [Difference in hours]×60
- **Total seconds** = [Difference in hours]×3600

## Worked example

Inputs — Start date: 2026-10-25; Start time: 10:00; End date: 2026-10-25; End time: 13:00; End time zone ahead of start by: -5 h.

Results — **Time difference = 8 h 0 min**; Days = 0; and hours = 8; and minutes = 0; Total hours = 8; Total minutes = 480; Total seconds = 28,800.

## FAQ

**How do I find the time difference between two times?**
Subtract the start from the end; add 24 hours for each day in between.

**How do I handle time zones?**
Convert both times to the same zone – subtract the end zone's offset relative to the start.

**How long is a flight from 10:00 London to 13:00 New York?**
8 hours (New York is 5 hours behind).

**What formula does the Time Difference Calculator use?**
Difference = (end date + end time − zone offset) − (start date + start time).