Over the years there have been quite a few dates put forth for the second gospel’s publication (publication here means put out for the public to have, hold, copy, etc). These range from as early as AD42 all the way to the second century.
Here I am going to list a few of the external sources that may or may not help narrow this date down. Then I hope you will chime in with your own opinion (including other external sources I may not have thought of).
Irenaeus (2nd century AD – c. AD202) writes:
Now Matthew published among the Hebrews a written gospel also in their own tongue, while Peter and Paul were preaching in Rome and founding the church. But after their death (literally “departure”) Mark also, the disciple and interpreter of Peter, himself handed down to us in writing the things which were preached by Peter. (Against Heresies 3.1.1-3)
It should be noted that the death of Peter and Paul is set during Nero’s persecution around 64AD.
In the anti-Marcionite prologue to Mark (dated to the second half of the fourth century AD by Helmut Koester) we find:
Mark declared, who is called “stump-fingered” because he had short fingers in comparison with the size of the rest of his body. He was Peter’s interpreter. After the departure of Peter himself, he wrote down this same gospel in the regions of Italy.
From Clement of Alexandria (c. AD150 – c. AD215) we have two separate testimonies to the dating of Mark. First:
But a great light of religion shone on the minds of the hearers of Peter, so that they were not satisfied with a single hearing or with the unwritten teaching of the divine proclamation, but with every kind of exhortation besought Mark, whose gospel is extant, seeing that he was Peter’s follower, to leave them a written statement of the teaching given them verbally, nor did they cease until they had persecuted him, and so became the cause of the scripture called the Gospel according to Mark. And they say that the Apostle, knowing by the revelation of the spirit to him what had been done, was pleased at their zeal, and ratified the scripture for study in the churches. (Eusebius, Hist. eccl. 2.15.1-2)
But that the Gospel according to Mark came into being in this manner: When Peter had publicly preached the word at Rome, and by the Spirit had proclaimed the Gospel, that those present, who were many, exhorted Mark, as one who had followed him for a long time and remembered what had been spoken, to make a record of what was said; and that he did this, and distributed the Gospel among those that asked him. And that when the matter came to Peter’s knowledge he neither strongly forbade it nor urged it forward. (Eusebius, Hist. eccl. 6.14.4-7)
Finally, we have Papias (before AD70 – c. AD155) saying of the connection between Peter and Mark, though not precisely on the date of his gospel:
And the Presbyter used to say this, “Mark became Peter’s interpreter and wrote accurately all that he remembered, not, indeed, in order, of the things said or done by the Lord. For he had not heard the Lord, nor had he followed him, but later on, as I said, followed Peter, who used to give teaching as necessity demanded but not making, as it were, an arrangement of the Lord’s oracles, so that Mark did nothing wrong in thus writing down single points as he remembered them. For to one thing he gave attention, to leave out nothing of what he had heard and to make no false statements in them. (Eusebius, Hist. eccl. 3.39.15)
There is an obvious disconnect at least between Irenaeus’ statement and Clement’s (and probably Irenaeus and the anti-Marcionite prologue against Clement). Irenaeus suggests that Peter and Paul were both dead (“departure” being a euphemism for death). Clement seems to suggest that Peter knew of the gospel (and in one statement seems to be please by Mark’s gospel, while in the other he is ambivalent to it).
Depending upon which of these to take at face value will determine whether we date the gospel before or after AD64.
Of course, simply establishing this date will not do on it’s own. If you say it is the upper limit to the writing of Mark, then you still must establish a lower limit (perhaps as low as AD42?). If you say that AD64 is the lower limit, well, then you must establish the upper limit.
If AD64 is the lower limit, then you must ask, was it written before or after AD70 (the date of the destruction of Jerusalem and the temple). If this is the upper limit then you have a firm date of the gospel of Mark to 64-70AD. If it is not the upper limit, then what is the upper limit? The beginning of the second century (as some have suggested)?
As for my own opinion? I don’t know. I am on the fence. I would say it was probably written in the 60’s (give or take a couple years). But I am unsure about whether it was before or after Peter’s death.