2699Y 
De-registered, 3818P
in.
So in effect, they converted a ASD slot to a WDD slot. Timings
at different sectors over the past week I've spotted 3818P tallies
with that theory:
1050hrs: PSR Dr 1 Blk 210 bus stop (to
Suntec)
1535hrs: PSR Dr 1 outside PSR MRT station bus stop
(to PSR Int)
1619hrs: Loyang Ave bus stop (to Suntec)
And then you add in the 1420hrs+ slot near Bras
Basah which others have spotted (in direction to Suntec), so you
have a Sv 518 DD that's effectively on A/P shift on Weekdays.
So it puzzles me even more why some peeps say they can't find a
Sv 518 DD on Weekdays. I'm not sure if 3818P runs on Weekends too,
but I think high chance it does since the e-tt change is for all
days and not only for Weekdays.
Hope the timings help those who want to sit a Sv 518 DD on
Weekdays, cheers. 
Makes sense on weekends also... If u see 502 has mostly DDs
plying on weekend. 518 should also get more on weekends considering
lot of ppl travel to Orchard area on weekends. I want to see DD on
30E next. It gets both AM and PM bet 55-60 pax. Deserves a DD for
long express route. Will also promote more ppl from Maple Tree/HF
to take it.
