C# Academy · Lesson

TimeSpan and Durations

Measure spans of time.

TimeSpan and Durations is a free C# Academy lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the C# Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

What Is a TimeSpan

While DateTime is a point in time, TimeSpan represents a length of time, like 2 hours or 90 minutes.

It is a duration with no calendar attached. You use it for stopwatch results, timeouts, and the gap between two dates.

Creating a TimeSpan

One constructor takes hours, minutes, and seconds: new TimeSpan(hours, minutes, seconds).

So new TimeSpan(1, 30, 0) is one hour and thirty minutes. The value prints in a clear h:mm:ss layout.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = new TimeSpan(1, 30, 0);
        Console.WriteLine(span);
    }
}

Factory Methods

Often it reads better to use a factory method. TimeSpan.FromMinutes(90) builds a span of 90 minutes.

There are matching helpers: FromHours, FromSeconds, FromDays, and FromMilliseconds.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = TimeSpan.FromMinutes(90);
        Console.WriteLine(span);
    }
}

Total vs Component Values

TimeSpan has two families of properties. Hours, Minutes, and Seconds are the broken-down components.

The Total... versions like TotalMinutes express the whole duration in one unit, as a decimal.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = TimeSpan.FromMinutes(90);
        Console.WriteLine(span.Hours);
        Console.WriteLine(span.TotalMinutes);
    }
}

Component vs Total Explained

For 90 minutes, Hours is 1 and Minutes is 30, because the duration breaks into 1 hour and 30 minutes.

But TotalHours is 1.5 and TotalMinutes is 90, since those count the entire span in a single unit.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = TimeSpan.FromMinutes(90);
        Console.WriteLine(span.TotalHours);
    }
}

Subtracting Two Dates

When you subtract one DateTime from another, the result is a TimeSpan.

This is the everyday way to find how much time passed between two moments, such as the length of an event.

using System;

class Program
{
    static void Main()
    {
        DateTime start = new DateTime(2024, 3, 5, 9, 0, 0);
        DateTime end = new DateTime(2024, 3, 5, 11, 30, 0);
        TimeSpan diff = end - start;
        Console.WriteLine(diff.TotalHours);
    }
}

Adding TimeSpans

You can add or subtract TimeSpan values with the normal + and - operators.

Combining two durations gives a longer one, which is useful for summing several intervals.

using System;

class Program
{
    static void Main()
    {
        TimeSpan a = TimeSpan.FromMinutes(45);
        TimeSpan b = TimeSpan.FromMinutes(15);
        Console.WriteLine((a + b).TotalMinutes);
    }
}

Negative Durations

A TimeSpan can be negative if the end is before the start, or after a subtraction.

The Duration method returns the absolute value, and Negate flips the sign. These help when you only care about magnitude.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = TimeSpan.FromHours(-3);
        Console.WriteLine(span.Duration().TotalHours);
    }
}

Comparing Durations

TimeSpan values compare with <, >, and == just like numbers.

This lets you check whether one duration is longer than another, for example to enforce a maximum allowed time.

using System;

class Program
{
    static void Main()
    {
        TimeSpan limit = TimeSpan.FromHours(2);
        TimeSpan used = TimeSpan.FromMinutes(150);
        Console.WriteLine(used > limit);
    }
}

Zero and Constants

TimeSpan.Zero represents no elapsed time, a handy starting point for sums.

There are also TimeSpan.MinValue and TimeSpan.MaxValue for the extreme bounds of a duration.

using System;

class Program
{
    static void Main()
    {
        TimeSpan total = TimeSpan.Zero;
        total += TimeSpan.FromMinutes(10);
        Console.WriteLine(total.TotalMinutes);
    }
}

Formatting a TimeSpan

You can format a TimeSpan with a custom string. For example @"hh\:mm" shows hours and minutes.

The backslashes escape the colon so it appears literally. For quick output, the default ToString is usually enough.

using System;

class Program
{
    static void Main()
    {
        TimeSpan span = new TimeSpan(2, 5, 0);
        Console.WriteLine(span.ToString(@"hh\:mm"));
    }
}

Quick Check

You have a TimeSpan of 90 minutes. Which property returns the value 1.5?

Recap

A TimeSpan is a duration. Build it with new TimeSpan(...) or factory methods like FromMinutes.

Component properties (Hours) differ from Total... properties. Subtracting two DateTimes yields a TimeSpan, and you can add, compare, and format durations.

Frequently asked questions

Is the “TimeSpan and Durations” lesson free?

Yes — the full text of “TimeSpan and Durations” is free to read here on the web, and the C# Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the C# Academy course, upgrade to CoddyKit PRO.

What will I learn in “TimeSpan and Durations”?

Measure spans of time. You practise C# Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start C# Academy?

No prior experience is required. C# Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “TimeSpan and Durations” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this C# Academy lesson?

Yes. Every C# Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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