A total of 574 couples booked a time slot to tie the knot at the Marriage Registry of Singapore on Nov. 11, 2011, a \"triple 11\" date. Information available from the marriage registry shows there are usually dozens of couples going to tie the knot on a normal day. On Nov. 14, for instance, 44 couples made appointments to tie the knot. Nov. 11 has been popular in some other countries and regions, too. In China, however, it is dubbed as the Day of the Singles. And even more popular is Nov. 20, which is recorded as \"20-11- 2011\" with a repetition of the number. There are 607 appointments. Local daily Straits Times said wedding planners and hotels were expecting good businesses.