Loop is returning the completely wrong value.

var transactionFeePercentage = 5M; // 5% processing fee (adjust as needed)
var processingFeePercentage = 10M; // 10% processing fee (adjust as needed)


var parkingBooking = new DateTime(12, 10, 7, 19, 0, 0);
var duration = TimeSpan.FromHours(2);

var bookingTotalMinutes = duration.TotalMinutes;
var bookingInterval = bookingTotalMinutes / 30;
var pricePerHour = 4M;

var subTotal = 0M;

parkingBooking.DayOfWeek.Dump();
parkingBooking.TimeOfDay.Dump();

for (int i = 0; i < bookingInterval; i++)
{
    DateTime currentIntervalStart = parkingBooking.AddMinutes(i * 30);
    DateTime currentIntervalEnd = currentIntervalStart.AddMinutes(30);

    decimal intervalPrice = (decimal)30 / 60 * pricePerHour; // Calculate price for the current interval
    
    if (currentIntervalStart.Hour >= 7 && currentIntervalStart.Hour < 14)
    {
        subTotal += intervalPrice; // Normal rate
    }
    else if ((currentIntervalStart.DayOfWeek == DayOfWeek.Friday || currentIntervalStart.DayOfWeek == DayOfWeek.Saturday) 
        && currentIntervalStart.Hour >= 17 && currentIntervalStart.Hour < 21) {
        subTotal += intervalPrice * 1.35M;
    }
    else if (currentIntervalStart.DayOfWeek == DayOfWeek.Sunday && (currentIntervalStart.Hour >= 17 && currentIntervalStart.Hour < 21))
    {
        subTotal += intervalPrice * 0.5M;
    }
    else if (currentIntervalStart.Hour >= 17 && currentIntervalStart.Hour < 21) {
        subTotal += intervalPrice * 1.15M;
    }
    else if (currentIntervalStart.Hour >= 14 && currentIntervalStart.Hour < 17)
    {
        subTotal += intervalPrice * 1.75M; // Rush hour rate (adjust as needed)
    }
    else
    {
        subTotal += intervalPrice; // Quiet period rate (adjust as needed)
    }

    Console.WriteLine($"Normal Rate {subTotal} : Multiplier {subTotal * 0.5M}");
}

var totalCost = subTotal;
var transactionFee = totalCost * (transactionFeePercentage / 100);
var processingFee = totalCost * (processingFeePercentage / 100);

totalCost += transactionFee + processingFee;

Console.WriteLine("Sub Total: " + subTotal);
Console.WriteLine("Total Cost: " + totalCost);

var providerCharge = subTotal * 0.30M;
var providerCut = subTotal - providerCharge;

Console.WriteLine("Provider cut: " + providerCut);
Console.WriteLine("Parklink cut: " + (processingFee + transactionFee + providerCharge));

Sunday
19:00:00
Normal Rate 1.00 : Multiplier 0.500
Normal Rate 2.00 : Multiplier 1.000
Normal Rate 3.00 : Multiplier 1.500
Normal Rate 4.00 : Multiplier 2.000
Sub Total: 4.00
Total Cost: 4.6000
Provider cut: 2.8000
Parklink cut: 1.8000