It isn't. Don't mix things up now. For normal dividends the ex-date is BEFORE the record date. This has to do with the settlement period. I think they changed it from T+3 days to T+2 days. So I don't know how many days exactly before the record date, 1 or 2. Oslo is probably following the same rules as everyone else here. Europe already had T+2 days (America changed it recently from T+3 to T+2 days).
The EXCEPTION to the rule are distributions > 25%. Now the ex-date is AFTER the record date (but apparently not in Oslo). Specifically, the rules state it has to be one day after the pay-date.