Originally Posted by
tentseller
Let's review the facts:
You arrive 11:30pm. You then go to transit hotel airside to sleep for six hours at 3:30am. This put us at 9:30am.
Your flight leaves late morning; at what time? Even if it departs 11:59am IMHO you would not have time to enter S'pore, take the SMRT into town, immediately return and get process by immigration for departure and security.
I believe you misunderstood the OP's plans. He arrives at 2330. Then he wants to spend the next four hours going into the city, rambling around before returning to the airport for his Transit Hotel reservation at 0330. He then sleeps for six hours until 0930 ... and then catches his onward flight.