This - Next - Following - Native English speakers please.

[Tachikaze]

It's not as easy as it would seem from this thread. Americans often differ on when they use "this" and when they use "next". As an ESL teacher and linguist, I have given it a lot of observation and thought. Here's how it seems to work (it's not pretty).

Sunday is easy. Starting from the next day it goes:
tomorrow
this Tuesday
this Wednesday
this Thursday
this Friday
this or next Saturday
next Sunday
next Monday

About the time you get to Wednesday, things aren't quite so clear. Here's how it seems to go.
Thursday is tomorrow
this Friday
this Saturday
this or next Sunday
next Monday
next Tuesday

There's a psychological barrier at Sunday or Monday, but only if that barrier is almost a week away. If that barrier is close, then the rule changes. See below.

From Friday:
Saturday is tomorrow
this Sunday
this Monday
this Tuesday
this or next Wednesday
next or this Thursday
next Friday

There is no strict rule.

[Es Arkajae]

I've used it for both if Thursday is a few days off for instance I may say "I've got something coming up next Thursday", or I may use 'this Thursday'.

It doesn't really matter, if theres chance you may be misunderstood or of it matters if you are just say 'Thursday after next' or 'Thursday week' or 'Thursday next week' etc.

English.. its a beautiful thing *sniff*

[English assassin]

if theres chance you may be misunderstood or of it matters if you are just say 'Thursday after next' or 'Thursday week' or 'Thursday next week' etc

That's good advice. This Thursday is always the very next thursday to happen, but next thursday could be ambiguous. "Thursday week" is a good idiomatic way to say the next thursday but one. (Well, its idiomatic in British English, I don't know about other sorts)

[Craterus]

Just go with instinct on "this" or "next". These guys have given good tips, but if you dont remember all the rules, just go with instinct. Worst comes to worst, you'll just have to give a date.