Time duration

Calculate a duration in hours and minutes, on the same day or into the next day.

Your dates and times stay in your browser and are not stored.

Method and assumptions

Method version 1.0.0 · Updated September 22, 2026

Clock duration

Formula: End minutes − start minutes + day offset

Minute-resolution wall-clock times, without dates or timezones. “Next day” adds 24 hours; midnight is never inferred automatically. Equal times give 0 hours on the same day or 24 hours the next day. Daylight-saving changes are not measured. Example: 23:30 → 01:00 next day = 1 h 30 min.

start: Start time
end: End time
day: End day

Gregorian calendar from years 0001 to 9999. Date, duration and rounding conventions are specified for each mode.

Calculate with code

These short examples use the same inputs and core calculation as this tool. Adapt validation and formatting to your application.

JavaScript

const minutes = (14 * 60 + 20) - (9 * 60 + 5);
console.log(`${Math.floor(minutes / 60)}h ${minutes % 60}m`); // 5h 15m

TypeScript

const minutes: number = (14 * 60 + 20) - (9 * 60 + 5);
console.log(`${Math.floor(minutes / 60)}h ${minutes % 60}m`); // 5h 15m

Python

start, end = 9 * 60 + 5, 14 * 60 + 20
minutes = end - start
print(f"{minutes // 60}h {minutes % 60}m")  # 5h 15m

Java

int minutes = (14 * 60 + 20) - (9 * 60 + 5);
System.out.printf("%dh %dm%n", minutes / 60, minutes % 60); // 5h 15m

int minutes = (14 * 60 + 20) - (9 * 60 + 5);
Console.WriteLine($"{minutes / 60}h {minutes % 60}m"); // 5h 15m