1) File a valid U.S. app on 20001208, no claiming of benefits/priority. The effective filing date is simply 20001208 (nice & easy).
2) Now, file a valid U.S. app on 20010101 that properly claims the benefit of a previous NPA (or claims priority on a previous PA) that was given a filing date of 20000101 (1 year earlier). The effective filing date is allowed to be the earlier 20000101 date! (Everything is within the U.S. here).
3) File a foreign application in a foreign country (Japan) on 19980622. Then later on (but within 1 year to allow for claiming priority on a foreign app) you file a normal NPA in the U.S. on 19990621. The U.S. filing date is the effective filing date even if you are able to claim priority on the foreign filing.
4) File an IA (remember an IA is different than just filing a foreign app) in Sweden (in Swedish) on 20001201 (after the 20001129 date), and it designates the US. On 20010220 WIPO publishes the app IN ENGLISH. Then later on, the app is brought into the U.S. national stage (35 U.S.C. 371(c)). The earliest effective filing date is allowed to be the original IA filing date of 20001129!
5) Take the above example, change the language that WIPO uses in publishing to anything other than English. NOW THERE IS NO DATE AT ALL FOR THE IA BEING BROUGHT TO THE U.S. STAGE UNDER 102(e). The dates used in 102(a) and 102(b) still apply in this case, they will be from the date that WIPO published (200010220), even though it was not published in English.
6) Same IA as seen in 4-5 BUT it was filed before the 20001129 cutoff date: IA filed in Sweden designating the U.S. filed on 20000101. WIPO publishes it on 20010701 (language does not matter). The app is then brought onto the U.S. Stage on 20020701. The earliest effective date under 102(e) is the date that the patent was brought onto the US national stage (20020701). However, remember that for 102(a),(b) the date is still when WIPO published on 20010701.
7) New example: IA is filed in Sweden, with the U.S. designated on 20010301 (after the cutoff). WIPO then publishes IN ENGLISH on 20020901. Later on, on 20030501, there is a BRAND NEW APPLICATION filed under 35 U.S.C. 111 (the normal way to file an app) in the U.S. that claims the benefit of the earlier IA filing. Because WIPO published in English, the U.S. app under 102(e) gets the 20010301 date from the original IA app.
Remember: Normally for foreign filings all you can do is get a foreign priority (with the filing date NOT going back to the foreign filing date), and even then it has to be done within 12 months (this is longer than 12 months). This situation allows a normal U.S. NPA to actually claim the benefit on an IA.
8) Same example as above, but WIPO DOES NOT PUBLISH IN ENGLISH: Because WIPO did not publish in English, the new 102(e) date is now 20030501, the date of the U.S. filing with no benefit claimed to the earlier IA. However, remember that 102(a)(b) are still in play with the date that WIPO published, which in this case is 20020901.
9) Now assume the IA gets filed BEFORE 20001129: IA filed on 20000301 (before the cutoff!) designating the U.S.. On 20010901 WIPO publishes the app (it does no matter what the language is). Later on 20011201 there is a brand new 35 U.S.C. 111 app in the U.S. trying to claim the benefit or priority of the original IA. The IA date doesnot apply, the 102(e) effective date is the same as the U.S. filing date of 20011201! (Before the 20001129 cutoff there was no claiming of a previous IA). However, the WIPO publishing date of 20010901 can still be used under 102(a)(b).