Third scheduled discount price

Hi,
I need to add a second scheduled discount price, exactly as into the default options. I mean, I will have the normal price, then an automatic discount price 2 months later for a duration of 3 months (normal price – 20%), then a last discount price for the last months (normal price – 30%). My products will only stay 6 months for sale.
So first price = normal price
Second price = normal price – 20%, from the third month to the 6th.
Last price = normal price – 30%, for the last 6th month.

With the default Woocommerce system I can schedule the first and the second price. I need to be able to schedule a third one.

Thank you for your help !

https://wordpress.org/plugins/woocommerce/