Plutarch, Romulus
Bernadotte Perrin, Ed.

12. Now it is agreed that the city was founded on the twenty-first of April, and this day the Romans celebrate with a festival, calling it the birthday of their country. And at first, as it is said, they sacrificed no living creature at that festival, but thought they ought to keep it pure and without stain of blood, since it commemorated the birth of their country. However, even before the founding of the city, they had a pastoral festival on that day, and called it Parilia.

[2] At the present time, indeed, there is no agreement between the Roman and Greek months, but they say that the day on which Romulus founded his city was precisely the thirtieth of the month, and that on that day there was a conjunction of the sun and moon, with an eclipse, which they think was the one seen by Antimachus, the epic poet of Teos, in the third year of the sixth Olympiad.¹ [3] And in the times of Varro the philosopher, a Roman who was most deeply versed in history, there lived Tarutius, a companion of his, who, besides being a philosopher and a mathematician, had applied himself to the art of casting nativities, in order to indulge a speculative turn of mind, and was thought to excel in it. [4] To this man Varro gave the problem of fixing the day and hour of the birth of Romulus, making his deductions from the conjunctions of events reported in the man's life, just as the solutions of geometrical problems are derived; for the same science, he said, must be capable not only of foretelling a man's life when the time of his birth is known, but also, from the given facts of his life, of hunting out the time of his birth. [5] This task, then Tarutius performed, and when he had taken a survey of the man's experiences and achievements, and had brought together the time of his life, the manner of his death, and all such details, he very courageously and bravely declared that Romulus was conceived in his mother's womb in the first year of the second Olympiad,² in the month Choeac of the Egyptian calendar, on the twenty-third day, and in the third hour, when the sun was totally eclipsed; and that he was born in the month Thoth, on the twenty-first day, at sunrise; [6] and that Rome was founded by him on the ninth day of the month Pharmuthi, between the second and third hour: for it is thought that a city's fortune, as well as that of a man, has a decisive time, which may be known by the position of the stars at its very origin. These and similar speculations will perhaps attract readers by their novelty and extravagance, rather than offend them by their fabulous character.