Please consider adding the following addtional predefined properties:
YYYYMMDD returning 20091204 for December, 4th 2009
HHMM returning 1604 for 4:04 PM
You offer the [Date] and [Time] properties, but these cannot be used as part of a file or directory name because they contain invalid characters.
We now use the following "Inline Script" Custom Action to create the YYYYMMDD property:
Session.Property("YYYYMMDD") = CStr(YEAR(Date()) * 10000 + MONTH(Date()) * 100 + DAY(Date()))