That depends on what I'm doing. Usually I have:
1) Daily profession cooldowns
2) Mission table (usually 3 times a day - morning, after work, before bed)
3) Mine and Herb garden (haven't skipped for about 3 weeks but man this is the real time sink)
4) Daily Profession Building Cooldowns (alch pot, scribe receipts, JC daily)
5) Trader on all 11 (invites to others garrisons)
6) Refill work orders on all buildings
7) Harrison Jones Quests for everyone
If I end up doing ALL of these it could easily take up 4 hours or more depending on the HJ quest. The HJ quests are a big time sink but I have him already on 1 character, 8 of them just need 1 quest at this point, so thats a huge amount of time gone soon.
If I do 1~5, it takes around 1:30~2:00 total. Refilling work orders only takes a short amount of time and I only really do it every couple days (2-3 usually).
I could easily cut out the mine at this point, but I *just* bought lvl3 on 3 characters so I feel compelled to at least farm it for a bit, though the benefits are severely lacking at this point. I have around 6,000 ore of each type banked and I'm running out of tab space in my gbank lol.
Besides this, every week I run BRF on my warlock (LFR) for stones, and I play with my guild on our "flex" Monday runs through BRF with my Warrior who just hit this quest point too. Thats about all the enjoyment I have out of the game at the moment. I plan to gear up the alts to run CM's, but thats a ways off still. I may just end up paying for carries (if thats even possible in WoD now) since I'm making so much gold and my CM team from MoP is mostly burnt out.