Netflix save money by changing subscription just before the payment date?

So, it's like I have a netflix subscription for 4 devices, but when I changed it, I got the message that there are no additional costs until the end of the month. Does that mean that theoretically I could change it the cheapest one day before and then pay 8 euro less? If so, I will not do it anyway, because it's actually scam, but I'm still interested

No, your new subscription will not be active until your old one has expired.

Then I could change it and wait until it was deducted and then go back to the end of the month and back shortly before. Then one never expires because it's active the day before and the day after billing.