using System;

​

public class Program

{

    public static void Main()

    {

        // example for UTC user

        var currentTime = new DateTimeOffset(2023, 08, 25, 6, 0, 0, TimeSpan.FromHours(0));     

        var dayOfWeekWithCurrentTime = currentTime.DayOfWeek.GetHashCode() - 1;

        var timeOfWeekWithCurrentTime = TimeSpan.FromDays(dayOfWeekWithCurrentTime) + currentTime.TimeOfDay;

        var result1 = TimeSpan.FromDays(7).Subtract(timeOfWeekWithCurrentTime).TotalDays;

        Console.WriteLine("UTC user is: " + result1);

        // example for (wrong) US user

        var currentTimeInProfileCulture = new DateTimeOffset(2023, 08, 25, 10, 0, 0, TimeSpan.FromHours(-8));

        var dayOfWeekWithCurrentTimeInProfileCulture = currentTimeInProfileCulture.DayOfWeek.GetHashCode() - 1;

        var timeOfWeekWithCurrentTimeInProfileCulture = TimeSpan.FromDays(dayOfWeekWithCurrentTimeInProfileCulture) + currentTimeInProfileCulture.TimeOfDay;

        var result2 = TimeSpan.FromDays(7).Subtract(timeOfWeekWithCurrentTimeInProfileCulture).TotalDays;

        Console.WriteLine("Wrong US user is: " + result2); // less than 3 days is wrong

        // example for (correct) US user

        var currentTimeInProfileTimeAndOffset = new DateTimeOffset(2023, 08, 24, 22, 0, 0, TimeSpan.FromHours(-8));

        var dayOfWeekWithCurrentTimeInProfileTimeAndCulture = currentTimeInProfileTimeAndOffset.DayOfWeek.GetHashCode() - 1;

        var timeOfWeekWithCurrentTimeInProfileTimeAndCulture = TimeSpan.FromDays(dayOfWeekWithCurrentTimeInProfileTimeAndCulture) + currentTimeInProfileTimeAndOffset.TimeOfDay;

        var result3 = TimeSpan.FromDays(7).Subtract(timeOfWeekWithCurrentTimeInProfileTimeAndCulture).TotalDays;

        Console.WriteLine("Correct US user is: " + result3); // just above 3 days is good (from Thursday evening to Sunday midnight)

    }

}