My bold has the same problem...!
I tried wiping the device.... upgraded it to the newest OS... and the problem is still there...
When I open my contacts... the birthdates of my contacts are correct... but when i forward my contacts to others.... the date would be 1 day earlier.... for example if the birthdate of the contact is 2 of Jan, when the contact is forwarded to my other contacts..... the date became 1 of Jan!!
Does anybody else have this problem and know how to fix it?
I trust that this is a software issue and not a hardware issue?