Purchase Date not Validated

If you are the original owner of the device, apple support will help here.

If you are not then you will have to use a service online (imei checker) to see the original activation date, these can cost money as only high up people can get this information & you can get scammed easily doing this, ie: fake information or just taking your money and running.

Are you you trying to find the warranty period? I have half the information or less. You need to tell us what you are trying to do. Check Your Service and Support Coverage - Apple Support

Can you provide more information? What is wrong with the device? What were you doing when the error happened? What have you done already to try and solve it?

What did it say when you used the link provided by welafever?

If you are not the original owner you cannot find this information out. If you are the original owner, contact your carrier to see when the device was activated.