I've found my solution.

for Europe fe. the DST starts on the last sunday 1:00 of march and ends on the last sunday of october.

You can calculate:

see this link

http://www.webexhibits.org/daylightsaving/i.htmlEuropean Economic Community:

Begin DST: Sunday March (31 - (5*y/4 + 4) mod 7) at 1h U.T.

End DST: Sunday October (31 - (5*y/4 + 1) mod 7) at 1h U.T.

Since 1996, valid through 2099

so I put this in a function that gives the adjusting seconds towards UTC for the European TZ, depending on the current date:

int adjustDstEurope()

{

// last sunday of march

int beginDSTDate= (31 - (5* year() /4 + 4) % 7);

Serial.println(beginDSTDate);

int beginDSTMonth=3;

//last sunday of october

int endDSTDate= (31 - (5 * year() /4 + 1) % 7);

Serial.println(endDSTDate);

int endDSTMonth=10;

// DST is valid as:

if (((month() > beginDSTMonth) && (month() < endDSTMonth))

|| ((month() == beginDSTMonth) && (day() >= beginDSTDate))

|| ((month() == endDSTMonth) && (day() <= endDSTDate)))

return 7200; // DST europe = utc +2 hour

else return 3600; // nonDST europe = utc +1 hour

}

Isn't that nice ?

Best regards,

Jeroen