You will find that on most days you will not have ten minutes of uninterrupted time to actually focus on and complete a task until the evening because the entire day has been spent responding to "urgent" emails and phone calls. It therefore becomes very difficult to predict when you will actually be able to complete something a client or partner has requested from you. I therefore recommend, when asked your ETA on such items, to say "as soon as is feasible." That day, folks, may never come.