Will all the just be resurrected at the same time?
No. The just are not resurrected all at once. They are raised in their particular lot or order, at separate times, as Daniel 12 indicates. There is a third aspect of resurrection still future, with intervals such as the extra 75 days after Christ's return and the tribulation.
Les explains that there is a third aspect of resurrection still future, after the corners and gleanings. In Daniel 12, from the time the daily sacrifice is taken away—the midpoint of the tribulation—there are 1,290 days, and then 1,335 days, adding 75 extra days between Christ’s return and the end of the tribulation. Daniel is told he will rest and stand in his lot. That word 'lot' is almost identical with the word 'order' in the New Testament. Therefore, all the just are resurrected in their particular lot or order, not all simultaneously, but at separate times.
But go thou thy way till the end be: for thou shalt rest, and stand in thy lot at the end of the days.