Generate random date and add 10 days RSS

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  xandeq

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  251 Points

  444 Posts

  Generate random date and add 10 days

  Jun 26, 2020 10:54 PM|xandeq|LINK

  I want to generate a random date and another date 10 days before that date.
  
  Lets say random generates a startdate 2020-05-01, so it would generate a enddate of 2020-05-11 . 
  The date couldn' be bigger than today date.
  
  Thanks in advance

• • Reply
  jzero

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  1101 Points

  673 Posts

  Re: Generate random date and add 10 days

  Jun 26, 2020 11:57 PM|jzero|LINK

  Just one idea. Using Ticks.
  Ticks are int64, so for random have to use NextDouble, it works, but can take a long time due to generated random outside range
  https://docs.microsoft.com/en-us/dotnet/api/system.random?view=netcore-3.1

  Protected Function RndDate() As DateTime
      Dim min As Long = New DateTime(1900, 1, 1).Ticks
      Dim max As Long = Now.Ticks
      Dim rand As New Random
      Dim randomDate As Long = rand.NextDouble * Int64.MaxValue
      Dim ok As Boolean = False
      While ok = False
        If randomDate < min Or randomDate > max Then
          randomDate = rand.NextDouble * Int64.MaxValue
        Else
          ok = True
        End If
      End While
      Dim NewDate As DateTime = New DateTime(randomDate)
      Return NewDate.AddDays(10)
    End Function

• • Reply
  xandeq

  Member

  251 Points

  444 Posts

  Re: Generate random date and add 10 days

  Jun 27, 2020 12:18 AM|xandeq|LINK

  jzero

  Just one idea. Using Ticks.
  Ticks are int64, so for random have to use NextDouble, it works, but can take a long time due to generated random outside range
  https://docs.microsoft.com/en-us/dotnet/api/system.random?view=netcore-3.1

  Protected Function RndDate() As DateTime
      Dim min As Long = New DateTime(1900, 1, 1).Ticks
      Dim max As Long = Now.Ticks
      Dim rand As New Random
      Dim randomDate As Long = rand.NextDouble * Int64.MaxValue
      Dim ok As Boolean = False
      While ok = False
        If randomDate < min Or randomDate > max Then
          randomDate = rand.NextDouble * Int64.MaxValue
        Else
          ok = True
        End If
      End While
      Dim NewDate As DateTime = New DateTime(randomDate)
      Return NewDate.AddDays(10)
    End Function

  Sorry. I meant in Javascript.

  Thanks!

• • Reply
  yogyogi

  Participant

  1253 Points

  943 Posts

  Re: Generate random date and add 10 days

  Jun 27, 2020 04:26 AM|yogyogi|LINK

  This is the way to add 10 days to a date in JavaScript:

  var someDate = new Date();
  var numberOfDaysToAdd = 10;
  someDate.setDate(someDate.getDate() + numberOfDaysToAdd); 

  To generate a random date see https://stackoverflow.com/questions/31378526/generate-random-date-between-two-dates-and-times-in-javascript/46093680

  Helping you always. Don't forget to click "Mark as Answer" on the post that helped you.
  ♠ ASP.NET Core Tutorials → Start from the Beginning and become an Expert in 30 days time ♠
• • Reply
  yij sun

  Contributor

  4060 Points

  1587 Posts

  Re: Generate random date and add 10 days

  Jun 29, 2020 06:50 AM|yij sun|LINK

  Hi xandeq,

  Accroding to your description,as far as I think,you could do like this:

   <script>
          function randomDate(start, end) {
              return new Date(start.getTime() + Math.random() * (end.getTime() - start.getTime()));
          }
          var startime = randomDate(new Date(2012, 0, 1), new Date());
          var endtime = new Date(startime.getTime() + (3600 * 1000 * 24*10));
          alert('startime:' + startime +'endtime:' + endtime);
      </script>

  Result:

  

  Best regards,

  Yijing Sun

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