Ok, first up this WON'T work for everyone, it all depends on your server (sorry for those not lucky enough!)
So, for AUSTRALIAN servers (the only servers I have tested) the daily profession cooldown has 2 DIFFERENT lockout periods if used in different locations (specifically inside garrison, and outside garrison)
When you use your daily INSIDE garrison the cooldown will reset at 2200 server time
When you use your daily OUTSIDE garrison the cooldown will reset at 0300 server time
This gives you the opportunity to get 2x the daily cooldowns if you use one first between 0300 and 2200 inside your garrison, and then one again between 2200 and 0300 outside garrison.
I believe some other servers have the reverse, and some servers don't have this at all.
Get in quick before Bliz changes the reset time to be universal!!