Allow-Empty
When this style is set, the Date-Entry shows an empty field when the Value property is not set or is set to zero. Without this style, a date is always shown in the control.
 
Example - Define a date-entry control that allows an empty value
screen section.
...
  03 screen-1-de-1 Date-Entry
     line 21.2
     column 49.5
     size 14.5 cells 
     lines 3.1 cells 
     id 17
     century-date
     allow-empty
     value-format davf-yyyymmdd
     .