19 HR delay. Ridiculous on the part of SQ.
Not to mention that since there are 180 transit pax with no home to go to, they were hopefully put up in hotels near the airport. When you have to round them all up after repairs, you're probably going to need to set a departure time that is quite conservative, and lets them get some rest as well.
Edit to say that there may have been some ICN-originating pax, have no idea how many