10 day rule
 

I am confused about the exact 10 day rule for ex europe XoneX tickets.
Would the following be allowed day 1 LHR-ORD.....day 10 SIN-LHR (arriving day 11) or would it have to be 10 clear days after leaving LHR ie day 11 SIN-LHR (arriving day 12).
Many thanks

The rule says "...commence no earlier than 10 days after..". If we were to use one day as a test travel could only start on day 2, so therefore I conclude the earliest you could board your SIN-LHR flight would be on day 11. That, of course, does not mean you should not try for a booking on day 10.

I've seen it (or the same rule in other fares) interpreted both ways - not counting date of first flight, and counting date of first flight.

There is no minimum for xONEx for ex-SWP AONEx and DONEx, but that is likely not much help to the OP (may help others).

I once had to plan around this 10 day min on a DONE4. I left LAX-LHR on Jan 7, and the earliest I could leave from MEL-LAX was Jan 17 - I think that is the 10th day if the day after the first segment is the first day. This worked out fine for me since Jan 16th was Presidents' day in the US and although I left MEL on Jan 17 (Tue) I also arrived into LAX on Jan 17th and was able to go straight to work.