Thanks for your answers, I guess the canadian F&D time schedule seems to have been worked out to stick to local conditions (i.e in northern areas where day light varies greatly with season.
If I inquired about ICAO standarts, it's because rules on this matter are still rather vague and derivated from fixed wings ops. and sometimes irrelevant to helicopters.
In fact, I just went accross ICAO Annex 6 part 3 amended on july 17th 06 and specific to helicopters. It points out that it is to each national Authority to define this schedule and it is exactly what the canadian Authority did.
For the time beeing we are trying to comply with this very basic schedule.
100 hrs per rolling 30 days, 30 hrs a week, max 7 days in a row followed by a day rest and a 12 hrs duty period with a max of 8hrs flying (crew of 2)
For now not much about split duty or else. Hopefully experience and and common sense will help to build a more comprehensive schedule and make it approved by the national Authority.