Hi, Bjorn.....
When a baptism is at the end of a year as in this case, it can be construed with high certainty that the birth occurred that year, because Catholics (in this instance)--even in those times--rarely would wait more than a year to secure an offspring's religious future.
Nonetheless, your suggestion would be more accurate, of course.
Unfortunately, many tree viewers tend to equate a baptismal date as a birth date, so.....I prefer to cite the baptismal date only where it is in exact response to its prompt--at the baptism section--and not to cite twice.
It all depends on where and time period. In old sources you only have baptism date, but at the same time is is very accurate because there was a period in for example Norway that the law required that a child should be baptized within 8 days after birth. In such cases using the baptism date in the birth date field would be more accurate than "before".
Academic and redundant for Mexico, cousin mine. Many times, a Mexican baptismal record will include the date and/or place of birth; there were/are no legal directives for baptism in Mexico where church and state now are legally separated. As you write, all these issues are country/time line dependent.....Carla