>I am trying to assign a date value to a variable like so:

>cWkStart = {16/12/2002 00:00:00}

>And when I check the value, cWkStart is blank. I tried set date to dmy, but that doesn't work.

Use DATE or DATETIME() Function.

cWkStart = DATE(2002,12,16)
***  or ***
cWkStart = DATETIME(2002,12,16,0,0,0)