I have Plutarch, Life of Pompey, 79, in front of me and I see no second date.
(Free translation, I study in french.)
"5. [...] He was fifty-nine years old and died the day after his birthday."
For the "Civil War", I don't have the reference at home, but I will check soon. I think there is a precise indication of the date of the murder of Pompey. Otherwise...