Did two sets when ATMA was a new thing first set 3 weeks full grind evenings and weekend (got Scorpion twice while doing a FATE passing by tho) second set I cannot tell did FATEs passing by when we did maps or other stuff in the area and while waiting on DF or PF to fill i "farmed" but I guess around 4-5 weeks as well (got here twice the one in Central Thanalan lol).
Decided to do a 3rd relic last week out of a mood (actually had no clue which class i'd do so checked Ironworks weps n chose out of the weps with worst stats there) took me around 8 hour to get all. Never passed much longer than 30 min in one area, actually did first 5 hours with a good friend rule one of us gets + max 5 fates.