Originally Posted by
WineCountryUA
SDC to the previous day (one-a-day) flight is not allowed. Impossible to meet the 24 hour rules (and still checkin rules).
There is a very small chance showing up at the airline, and airport agent will make the change.
Originally Posted by
EWRSNA
Couldn’t they SDC to the 10:30pm SFO-EWR, connecting to the 8:30am EWR-LHR?
As
EWRSNA mentioned, the OP could SDC to the flights above but he/she should do the SDC at 15:05 on 23 Dec.