Strange, that should work as expected. It should apply the promotion as long as the purchase is made after 07-01 of the current year. I'm having a hard time understanding what you mean in your below reply though.
www.joomlapolis.com/forum/277-cb-paid-subscriptions-support/242399-how-to-spilt-the-subscription-year?start=0#319759
So it's only working if they purchase before 07-01? Note you mention registration date, but the condition is based off the order date. If you want it to be based off the registration date then you need to make the below change.
Date A, Field A or Value A: Following CB field
CB Field A: registerDate