When was the Gospel of Thomas written?

There is plenty of evidence to point to a first century composition. The honorific titles Jesus enjoys in the Gospel of John are not referenced in Thomas suggesting that the author was unfamiliar with such terminology. Where there are parallels to the Synoptic Gospels then the Thomas  version tends to be pithier and less manufactured. Unlike the Synoptics, Parables are not explained for this is a Jesus who has no particular need to explain his teaching.