The layover used to be much less than what it is now. It used to depart at around 11am-1pm with an arrival back at about 5-6pm. They changed it to an evening departure from SIN due to business demands etc.

My wife used to love this layover as Crew. She used to get into SIN at around 8am, sleeps till about 4pm, goes out in evening for shopping, dinner and party, gets back to the hotel at around 2-4am, sleep till about 2pm, fly back to India at 5pm.

Hong Kong is also the same.