Jeez you must really love your tucker mate.
I regularly take the SQ afternoon flight and have 10/12 hour layover in SIN before continuing to PVG, CAN or PEK - fabulous nightlife in SIN albeit expensive - but spending a day their eating aint gonna be on my radar.
Taking an afternoon flight, then continuing on to another day flight after 10/12 hours makes sense. Taking an overnight flight at 0250 and then another overnight the next night, with only a small change in time zone does not, unless travelling to somewhere much further than PEK!