You’ll still set up one ticket per buying interval,
so one ticket for April & May at $40 where the sale end date is May 31,
and another ticket for June at $50 where the sale start date is June 1,
then so on.b You do not need to set up multiple datetimes, you’re only setting up multiple tickets to handle the different pricing schemes.
Then, you can hide the future ticket options by adding the following CSS to your Appearance > Customize > Additional CSS panel: