The timeslot record is a breakdown of the week in half-hour chunks, indicating available time for dynamic scheduling. When applied to a user record, it represents the working week, but can also be set against a project restricting when that project can be scheduled.
Although the timeslot record limits availability of resources and projects within half-hour chunks, that does not mean dynamically scheduled tasks and projects are limited to half-hour boundaries. The granularity of the scheduling engine is set in system settings, and can be as low as one minute.
Project timeslot settings are inherited by newly created sub-projects, but can thereafter be changed. If both user timeslots and project timeslots are defined, and there is no overlap, then the project cannot be scheduled, and a conflict alert will be generated. For example, if one project tree contains domestic tasks limited to evening activity, and another contains business tasks for the working day, and the user timeslot spans both time periods, then both sets of projects will be arranged accordingly. Most implementations will define user working hours, leaving project timeslot restrictions clear.