The latest pre-release version of Suprtool has a new conversion routine that converts dates to a Julian date number (where 1 = Jan. 1, 4713 BC). Because ASK dates are also a form of Julian dates (based on Nov. 1, 1971) it is possible to create ASK dates in a couple of steps.
The example below converts a file of ccyymmdd dates to Julian dates, then subtracts the constant between ASK and Julian dates. The third step is just a "proof" step that converts the ASK dates back to ccyymmdd dates to show that they are equal to the original file's dates.
in myfile
def cymd,1,8,display
item cymd,date,ccyymmdd
def juldays,1,4,integer
ext cymd, juldays = $days(cymd)
out myfile2,link,temp
xeq
IN=3, OUT=3. CPU-Sec=1. Wall-Sec=1.
in myfile2
def askdate,1,2,integer
ext askdate = juldays - 2441255
ext cymd, juldays
out myfile3,link,temp
x
IN=3, OUT=3. CPU-Sec=1. Wall-Sec=1.
in myfile3
item askdate,date,ask
def newdate,1,8,display
ext newdate=$stddate(askdate)
ext cymd,juldays,askdate
list standard
x
Jul 29, 1999 9:56 File: MYFILE3 Page 1
NEWDATE CYMD JULDAYS ASKDAT
19990729 19990729 2451389 10134
19730101 19730101 2441684 429
20000101 20000101 2451545 10290
IN=3, OUT=3. CPU-Sec=1. Wall-Sec=1.
[Paul Gobes]