Calculate relative time in C#

Question

Given a specific DateTime value, how do I display relative time, like:

• 2 hours ago
• 3 days ago
• a month ago

Answer 1

I would provide some handy extensions methods for this and make the code more readable. First, couple of extension methods for Int32.

public static class TimeSpanExtensions {

    public static TimeSpan Days(this int value) {

        return new TimeSpan(value, 0, 0, 0);
    }

    public static TimeSpan Hours(this int value) {

        return new TimeSpan(0, value, 0, 0);
    }

    public static TimeSpan Minutes(this int value) {

        return new TimeSpan(0, 0, value, 0);
    }

    public static TimeSpan Seconds(this int value) {

        return new TimeSpan(0, 0, 0, value);
    }

    public static TimeSpan Milliseconds(this int value) {

        return new TimeSpan(0, 0, 0, 0, value);
    }

    public static DateTime Ago(this TimeSpan value) {

        return DateTime.Now - value;
    }
}

Then, one for DateTime.

public static class DateTimeExtensions {

    public static DateTime Ago(this DateTime dateTime, TimeSpan delta) {

        return dateTime - delta;
    }
}

Now, you can do something like below:

var date = DateTime.Now;
date.Ago(2.Days()); // 2 days ago
date.Ago(7.Hours()); // 7 hours ago
date.Ago(567.Milliseconds()); // 567 milliseconds ago