This issue is fixed in version 1.0v3.
ClarisImpact 1.0v1 and 1.0v2 do not correctly calculate when using weeks with less than seven days. The most common example is the five-day week (excluding Saturday and Sunday). Try this example to see the issue:
1. Create a new Custom Timeline with a five-day week.
2. Change the Data Display... to show Duration and Planned Start.
3. Change the Duration of the first Task to be 1 day.
4. Change the Planned Start to February 18th, 1994 (Friday).
Notice that Task 2 calculates the Planned Start as Saturday even though you have told it to calculate based on a five-day week.
Workaround:
In the above example, change the Duration in Task 1 to be 1.01 days. The Planned Start in Task 2 will now calculate correctly. In general, add .01 to any duration where the dates are not being calculated correctly.