The Mishnah preserves only two prayers and a maxim in his name, enough to place him among the tannaim of the generation around 70 CE but not enough to fix an actual birth year, and almost nothing else about his life survives.
What would resolve this An external documentary or epigraphic record naming a birth year, independent of the brief mishnaic attributions and of the later medieval kabbalistic ascriptions made in his name.
OpenRabbinics, history of the Second Temple and Mishnaic periodGershom Scholem, Major Trends in Jewish Mysticism