How soon after birth should a child be christened in Norway?

To find an answer to this question you should consult the Norwegian Encyclopedia Store Norske Leksikon available online. Christening in Norway

Early Christening Rules and Laws
In the Middle Ages it was punishable by law to wait more than 8 days to have an infant baptized. This is according to King Christian the 5th Norwegian Law of 1687. It was believed that if a child died without baptism this child’s soul would be lost forever, therefore it was very important to the parents of a child to have the child baptized as soon as possible. This law was abolished in 1771, but in the 1800s an infant was usually baptized within 1-3 days after the birth. Baptism was deemed as necessary to be “saved”, and it was only the clergy who should perform the baptism. However, this caused a problem, as children were usually born at home, many on a farm far away from the parish church, or where the minister resided. It was impossible for the minister to baptize every child in the congregation within a few days unless the child was brought to the church. This brings up another question. Who should baptize the child? Often a child died shortly after birth, and there was no time for the minister to get there. Therefore it was necessary to give instructions about how an infant was to be baptized. Clean water was to be used, but in some cases beer was used if clean water could not be found. If an infant looked sickly or death was imminent, the baptism could be performed by the father of the child, the midwife or even the mother. In the church records you will often see en entry that a child had been baptized (hjemmedøbt) at home. This baptism, if the child lived, would be confirmed by the minister in the church at a later time. The confirmation of a christening or baptism is not to be confused with the confirmation process that took place when a child was between 13-18 years of age.