Day 1 technically starts the minute you put them in the incubator. So for yours, it would be 7 pm Friday evening was the end of day 1. But for simplicity's sake, most people use the rule that if you set them in the evening, the next day is counted as day 1. Thursday the 16th would be hatch day.
Were these shipped eggs? If so, you are better off handling them as little as possible. I wouldn't check for veining until at least day 7. Try to check them without picking them up if at all possible. The egg is so fragile already from being shipped, moving it too much could cause it to die. Never check for veins at day 3, it is possible to see them, but highly unlikely unless you are a pro, and have a really really good candler! Shipped eggs or not, it is best to not handle them anymore than you have to.