Catholics Fulfilling Their Sunday and Holy Day Obligation to Attend Mass Who are Late

It is a precept of the Catholic Church for one to attend Holy Mass on Sundays and Holy Days of obligation. I have not received a uniform answer to the following question, so I pose it here hoping that someone who is certain of an answer may post it: How late can a person arrive at Mass, say on a Sunday, in order for that Mass to fulfill that person's obligation to assist at Mass? *Note:* One person told basically told me: *up to the Consecration*; another said *before the Gospel reading*.