CreateSampleData.cs

using System;
using System.Globalization;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            var now = new DateTime(2020, 5, 23);
            var random = new Random();
            for(var i = 0; i < 48*7; i++)
            {
                Console.WriteLine(
                    $"{{" +
                    $" \"Date\": \"{now.AddDays(-1 * i).ToString("yyyy/MM/dd")}\"," +
                    $" \"DayOfWeek\": \"{now.AddDays(-1 * i).ToString("ddd", new CultureInfo("en-US"))}\"," +
                    $" \"Data\": {random.Next(50, 200)}" +
                    $" }},"
                    );
            }
        }
    }
}