First time hiking advice?

Hi! I'm a pretty experienced hiker on trails in and around the finger lakes, but I've never hiked in the adirondacks before, and I want something that's a challenge but won't endanger my life unnecessarily. I will have a hiking partner, and both of us are 18 and in good shape.



Now, my preference is Mount Marcy, and I'd like to know if this is possible to accomplish in one day? We'd be going sometime during July or August. I could just use all the information I can.



If this is too much of a challenge, we'd go with Buck Mountain instead, but would really love to do the challenge of Marcy.



Thanks!