I think we're talking past each other. I'm not referring to a percentage of time being consumed by meetings and such; I'm referring to how frequently I'm asked

I think we're talking past each other. I'm not referring to a percentage of time being consumed by meetings and such; I'm referring to how frequently I'm asked to multitask because several urgent projects are going on at once. New priorities are added unpredictability, and sometimes I'm asked to clear all other work off my plate to fight some fire. Of course that's a sign of trouble, but it's natural for the stage this company is at. (Note: different company than the one that did the lognormal study I mentioned a few posts ago, and a different role for myself, much more directly exposed to customer issues). In an environment like that, calendar estimates are completely nonsense because the priority list itself is volatile on the timescale of the estimate. But work estimates can still be stable; I can still accurately report that I have eight hours of work left on issue A, and when I provide that estimate along with work estimates on issues B and C which are also assigned as "top" priorities, management can use that to decide whether I'll finish issue this week or not. If you're sufficiently informed to know what your priorities will be on the timescale of an estimate, you can make reliable calendar estimates.