Weather forecast one day short

Using WeatherKit I want to get a 5-day forecast starting tomorrow, however, I only get 4 elements in the forecast. What am I missing here?

public func updateWeather()async{
        guard locationManager.location != nil else {locationManager.updateLocation(); return}
        if self.needsUpdating{
            
            let startOfToday = Calendar.current.startOfDay(for: Date())
            let endOfToday = startOfToday+24*3600

            let firstDay:Date = endOfToday+1
            let lastDay:Date = firstDay+(5*24*3600)
            futureWeather = try? await WeatherService.shared.weather(for: locationManager.location!,
           including: .daily(startDate: firstDay, endDate: lastDay)
            )
            
        }
    }