The Board consensus is that the baptism took place on a Sunday, and, thus, the murders took place on a Sunday.
Is that a fact?
I don't know that it's the "consensus" here, as I don't ever recall discussing it. But I can say with absolute certainty that I've never been to a Catholic Baptism that
didn't take place on a Sunday (and I've literally been to a hundred). To me, it's a joyous, personal holiday, which has always been associated with taking place on a Sunday.