AST is an abbreviation for Abrama Standard Time. This time scale refers to a time that is unknown in both origin and duration. A person is said to be on AST when their ability to adhere to any type of standard time frame is absent or completely out of synch with Universal time.
Andrew will meet with us today at 10:00 AST. This means that we can be sure that the actual time Andrew will show up for the meeting will be unknown (if at all).