3755L from S to A/P shift.
276Y is still on S shift, rotating between 15S & 16S.
3863H & 3783E will rotate between 15S, 16S & 17E, that's
why you see 3783E or 3863H doing the 17E for 2 consecutive weeks to
cover up for 276Y.
Dunno why 276Y doesn't do 17E, the 179 x-over... 
For 242, Weekday 33 & Weekday 35 (the one in use now) is
exactly the same.
Weekday 34 was used for IMF period.