Q:

Random Time Generator for time betweeen 7AM to 11AM

I am creating a test file and I need to fill it with random times between 7AM to 11AM. Repeating entries are OK as long as they aren't all the same
I'm also only interested in HH:MM (no seconds)
I don't know where to start. I did Google before posting and I found an interesting search result
www.random.org/clock-times/

Only issue is that all times "randomly" generated are in sequential order. I can put it out of sequence once but I need to generate 100 to 10,000 entries.
I am hoping to create a WinForm C# app that will help me do this.

A:

Create a DateTime value for the lower bound, and a random generator:
DateTime start = DateTime.Today.AddHours(7);
Random rnd = new Random();

Now you can create random times by adding minutes to it:
DateTime value = start.AddMinutes(rnd.Next(241));

To format it as HH:MM you can use a custom format:
string time = value.ToString("HH:mm");

A:

Calculate the number of minutes between your start and stop times then generate a random number between 0 and the maximum number of minutes:
Random random = new Random();
TimeSpan start = TimeSpan.FromHours(7);
TimeSpan end = TimeSpan.FromHours(11);
int maxMinutes = (int)((end - start).TotalMinutes);

for (int i = 0; i < 100; ++i) {
   int minutes = random.Next(maxMinutes);
   TimeSpan t = start.Add(TimeSpan.FromMinutes(minutes));
   // Do something with t...
}

Notes:

You should only create one random object, otherwise you will get many duplicates in a row.
The start time is inclusive but the end time is exclusive. If you want to include the end time too, add 1 to maxMinutes.

A:

Here is a generic method to give you a random date between a given start and end date.
public static DateTime RandomDate(Random generator, DateTime rangeStart, DateTime rangeEnd)
{
    TimeSpan span = rangeEnd - rangeStart;

    int randomMinutes = generator.Next(0, (int)span.TotalMinutes);
    return rangeStart + TimeSpan.FromMinutes(randomMinutes);
}

If you use something like this a lot you could make it an extension method on Random.

