Try like this
=Weekday(date#('01/01/2012','DD/MM/YYYY'))& ' '&day(date#('01/01/2012','DD/MM/YYYY'))
=Weekday(DateField) &' '&Day(DateField)
if date format is in correct format..
Hope it helps
load in sxcript like that .ex:
Load *, weekday(Datefield)&''&Day(Datefield) as WeekDayField from tablename;
Then use that in chart as dimension