Right now with ZCS 18.104.22.168 and ZCO 6.0.6031.8 (a pre-release provided by support), I find that I can't see others' free-busy in Outlook past a point exactly 54 days in the future counting from the time I launch Outlook.
Quitting and relaunching Outlook resets the counter. For example I launched Outlook at 2:35 PM just now and I couldn't see free-busy for other users past 2:35 PM 10/24. Things stayed that way until I quit & restarted at 2:38 PM. Now I can't see free-busy past 2:38.
Can anyone else confirm this bug, on a recent ZCO?