If the column you are reading from is actually a character column, and not a numeric column with a format applied to it, then the substring is what you want to use. Make sure the column is a character column. and if so, the below will work
a="Thu 01/02/2020 10:42 PM";
b=substr(a,5);
The formula version of the above code if the original column is called "MyColumn"
substr(:MyColumn,5);
If not then you just need to change the format for the column
Jim