weaning calves

I weaned my two boys by the moon phases. The man who always told us when to do it is no longer around. My parents are adopting a baby and want to start weaning him. They remember how easy it was with our kiddos and we are trying to find out when is the earliest time to do it. any help would be appreciated.

I'll ask my hubby. He works for a guy that has a steer-cow-bull business. I'll get back to you.