Question: Can we sacrifice an animal which was born at Eid al-Adha two years after its birth? Do we calculate the age of animals according to the current or lunar calendar?
Lunar calendar is the basis for calculation of sacrificial. That lasts 354 days. An animal of cattle that was born at Eid al-Adha would have completed its second age two years (current calendar) after its birth. Therefore, it can be sacrificed.
You may use the following link for determination of cattle age: