[mellett68]

I have been keeping one day a week for the manager's schedule- style calls and appointments.

The rest of the week is divided in to half-day blocks which from my own experience is the minimum useful time to switch context and complete or work on some task.

I'd never read this before but it sums up problems I've had in teams previously with scheduling and especially short-notice "quick" meetings that wreck an afternoon.

It also means there's sacred time in my calendar for unbillable stuff, which gives peace of mind rather than thinking "but I could be doing..."