Gotta chuckle about this one! I always have arguments with my 15 year-old about this. For me, it's simple: If I say "this" it means in the current week; if I say "next", it means in the following week. I see the use of "next" here as distinct from "the next", which is a different beast. Since this is by no means standard, I sometimes clarify with "this coming", especially when, say, it's Monday, and I'm talking about Sunday. But I've never totally missed something from confusion about it, but probably because people use dates. Which, by the way, the entire world does sensibly, EXCEPT the US, with our M/D/Y nonsense instead of the logical D/M/Y. :0)