using System;

​

var initialDate = new DateTime(2024, 05, 20, 22, 50, 0, 0);

for (var i = 0; i < 200; i += 2)

{

    var currentDateTime = initialDate.AddMinutes(i);

    Console.WriteLine($"{currentDateTime} = {GetDelayByParabola(currentDateTime)}");    

}

​

return;

​

static double GetDelayByParabola(DateTime scheduleDateTime, int focalRadiusInMinutes = 30, int maxDelayInMinutes = 15) =>

    Math.Min( Math.Abs(((scheduleDateTime.Hour >= 12? 1440 : 0) - scheduleDateTime.TimeOfDay.TotalMinutes) * maxDelayInMinutes / focalRadiusInMinutes)

        , maxDelayInMinutes);