if the field is a Date/Time field then you must enter
a complete date (regardless of the format).
This is just NOT TRUE. There are two short-hand ways to enter dates:
mm/yyyy -- will be stored as mm/1/yyyy
mm/dd -- will be stored as mm/dd/current year
Now, there are potential problems, such as a display format that is
in conflict with the localized Windows date formats, e.g., a
computer with d/m/y default date format will have incorrect results
if you enter in m/d/y format.
Also, you must avoid mm/yy format, for two reasons:
1. the Y2K window means that guesses are made about the century
intended.
2. 2-digit years that could also be days will be interpreted as a
date, e.g., 07/13 for July 2013 will be stored as July 13, 2009.