Welcome to this Forum!

From what I've read and from my own recent personal experience (taking 54% cigars and slowly getting them to 64%), I would say it will take 2-3 weeks. While my cigars did not suffer longterm from being at 54% (ish) for a few months, I noticed they were dryish and when I clipped the cap, the cap kind of shattered into lots of pieces. After about three weeks, the caps were staying together again. I could also "see" a difference in the way the cigars looked and felt in my hand. Granted I would need many, many years before I could take a 54% and a 64% cigar in each hand and tell you definitively which was which. I just know for now that there was a difference.

However, I don't think it should take that long to go from 62% to 68%. I don't think your cigars will care all that much either....