Random Time Generator for time betweeen 7AM to 11AM

Question

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.

Solution 1

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.

Solution 2

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");

Solution 3

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.

Solution 4

Create a Random object and use that to create a new DateTime

Random rand = new Random();
//Note that Random.Next(int, int) is inclusive lower bound, exclusive upper bound
DateTime myDateTime = new DateTime(2012, 11, 27, 
    rand.Next(7, 11), rand.Next(0, 60), 0);

Then use the time output where you want it.

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Comments

[kaveman]

pick a random number h [7,11]. If h < 11, pick another random number m [0,59], else m is 0

[kaveman]

Note this solution has the possibility of picking times > 11:00am, e.g. 11:15am

[kaveman]

but now 11:00am is not possible...

[Cocoa Dev]

how do I use t like get the time?