Try this one:

IF BarIndex = 0 THEN
IF OpenMonth < 3 OR OpenMonth > 10 THEN
DSTon = 0
ELSE
DSTon = 1
ENDIF
Sundays = 0
ENDIF

// Determine the day of the week for the second Sunday in March when DST turns ON
IF (OpenMonth = 3) AND (DSTon = 0) THEN
IF OpenDayOfWeek >= 0 AND (OpenDayOfWeek[1] > OpenDayOfWeek) THEN
Sundays = Sundays + 1
IF Sundays = 2 THEN
DSTOn   = 1
Sundays = 0
ENDIF
ENDIF
ENDIF

// Determine the day of the week for the first Sunday in November when DST turns OFF
IF (OpenMonth = 11) AND (DSTon = 1) THEN
IF OpenDayOfWeek >= 0 AND (OpenDayOfWeek[1] > OpenDayOfWeek) THEN
DSTOn   = 0
ENDIF
ENDIF

// Define trading hours based on DST status:
IF (OpenDayOfWeek = 5 AND ((OpenTime >= 200000 AND Not DSTon) OR (DSTOn AND OpenTime >= 190000))) OR (OpenDayOfWeek = 0) THEN
TradingDay = 0
ELSE
TradingDay = 1
ENDIF
Return TradingDay

robertogozzi wrote:

Try this one:

Roberto, your code does virtually nothing, because it is not (or will not be) about Daylight Savings as such, sec;
You would not care a hoot whether your Italian stocks etc. open one hour earlier or later in relation to sun dawn when summer time has arrived next week (don’t even try to reason about the earlier or later if you want to survive this day 😉 ). What is important is the relation to the world markets. Thus, the past two weeks and the current week, the US markets open and close 1 hour earlier than Europe’s, because THEIR DLS already started two weeks ago; ours is just to come.
In principle the same thing will happen in autumn (the US will be early) but whether the period takes 3 weeks again, is to be seen (I did not look it up yet).

All we can say is that for Europe the rules are quite decent (your code contains that) and that for the US they seem to do what they like, or I don’t know the rules (why this idea ? because it is different often, like 1 week of difference, 2 weeks of difference, or 3 weeks of difference like currently). But hey, if you travel 10 States, you must change your watch 10 times. 🙂