It is not normally possible to copy and paste a date from a ClarisImpact Table into a ClarisImpact Timeline date cell. While ClarisImpact will allow you to paste the date, it will beep at you and change the date back to the original when you try to move to another cell. This is because ClarisWorks and ClarisImpact store dates internally as serial numbers.
This does not happen when pasting into a Time line date cell that is empty and has never had a date entered into it.
If you copy a text date value from the ClarisImpact Table (where you enter ="3/1/94"), it will paste without a problem.
Also, =DateToText(Date(Year(A1), Month(A1), Day(A1))), entered into A2 (or any other cell), gives a result that can be copied from A2 and pasted into a timeline date cell.
Other programs work fine when copying and pasting a date to a ClarisImpact Time line. One example would be FileMaker (actually, if it is a calculated date copied from FileMaker to a ClarisImpact Time line it will also not work). ClarisWorks Spreadsheet dates also copy and paste fine.