I used TTOC(mytable.mydatetime) as part of my index

My whole index looks like ALLT(mytable.myname+TTOC(mytable.mydatetime)

myname is CHAR 30
mydatetime is DATETIME 8

When I SEEK on the Index it never finds the record I am seeking because
SEEKID looks like STEVE KRAMER01/25/2002 15:50:51
If I look at the record I am seeking it looks like 01/25/2002 03:50:51 PM

How can I resolve this time mismatch? I believe I SET HOURS to 24-hour clock in my forms. I have never tried using a DATETIME in an index before, just a DATE or a TIME. Thanks for the help!