When I set up a project and allocate resources I sometimes find that the duration changes and I'm left with durations with fractions of a day.

When it happens I have total days in sub tasks but the summary task shows fractions. i.e. if I allocate 20, 45, 120, days etc. to sub tasks the summary task will show 185.36 or similar.

What causes this? Is it possible to suppress it?

One of two things will cause this effect:

1. There is a mismatch between the default calendar settings in Tools|Options|Calendar and the settings in Tools|Change Working Time.

2. The summary task is set to calculate the total duration between the start time of the earliest subtask and the finish time of the latest subtask. If the any of the tasks durations are in hours, this is where the fractions come from.

The first is resolvable - the default calendar settings must be for a working day which is LONGER than the Change Working Time calendar. However, this would mean copying all tasks in the project and pasting into a new project file with the new default settings.

The second is not resolvable and cannot be suppressed.

Good luck!

Thank you Alan, I suspected it may be a calendar mismatch, but did not know where exactly.