can provide a new funtion which can judge a datetime is DaylightSavingTime(DST) or not ,like java

[chuangmingjijing]

java:

ZoneId zoneId = ZoneId.of("America/New_York");

LocalDateTime localDateTime = LocalDateTime.of(2023, 05, 30, 15, 16, 17);//datetime in java
ZonedDateTime zonedDateTime = localDateTime.atZone(zoneId);
System.out.println(zonedDateTime);

ZoneRules rules = zoneId.getRules();
boolean result = rules.isDaylightSavings(zonedDateTime.toInstant());
System.out.println("the time is dst or not："+result);

in mt5 like this will be great.

datetime dt = D'2023.05.30 15:16:17';
bool res = isDaylightSavings("America/New_York",dt);

i already read ariticle about "deal with time" many times, part 2 is so complex for me who is beginer.  

thanks a lot.

Dealing with Time (Part 1): The Basics - MQL5 Articles

Dealing with Time (Part 2): The Functions - MQL5 Articles

[amrali]

See this, it might help you

https://www.mql5.com/en/code/27860

[Hong Yi Li]

chuangmingjijing:

java:

in mt5 like this will be great.

i already read ariticle about "deal with time" many times, part 2 is so complex for me who is beginer.  

thanks a lot.

Dealing with Time (Part 1): The Basics - MQL5 Articles

Dealing with Time (Part 2): The Functions - MQL5 Articles

This is my current method for calculating daylight saving time. Maybe you can refer to it. I hope it will be helpful to you.

input string G_GMTandDSTSettingn = "---------- GMT and DST setting ----------"; // |
input string G_BrokerGMTOptions  = "The time zone of most brokers is GMT+2.";
input int    G_BrokerGMTType     = 2;
input string G_BrokerDSTOptions  = "0=United States, 1=European Union, 2=On, 3=Off.";
input int    G_BrokerDSTType     = 0;

bool AutoDST()
{
   MqlDateTime mqlTime;
   TimeToStruct(TimeCurrent(), mqlTime);
   if (G_BrokerDSTType == 0)
   { 
      MqlDateTime firstDayTimeMarch, firstDayTimeNovember;
      firstDayTimeMarch.year = mqlTime.year;
      firstDayTimeMarch.mon  = 3;
      firstDayTimeMarch.day  = 1;
      TimeToStruct(TimeCurrent(firstDayTimeMarch), firstDayTimeMarch);
      int L_firstSundayOfMarch  = (firstDayTimeMarch.day_of_week == 0) ? 1 : (8 - firstDayTimeMarch.day_of_week + 1);
      int L_secondSundayOfMarch = L_firstSundayOfMarch + 7;
      firstDayTimeNovember.year = mqlTime.year;
      firstDayTimeNovember.mon  = 11;
      firstDayTimeNovember.day  = 1;
      TimeToStruct(TimeCurrent(firstDayTimeNovember), firstDayTimeNovember);
      int L_firstSundayOfNovember = (firstDayTimeNovember.day_of_week == 0) ? 1 : (8 - firstDayTimeNovember.day_of_week + 1);
      bool L_USADSTOpen  = mqlTime.mon >  3 || (mqlTime.mon ==  3 && mqlTime.day >= L_secondSundayOfMarch  );
      bool L_USADSTClose = mqlTime.mon < 11 || (mqlTime.mon == 11 && mqlTime.day <  L_firstSundayOfNovember);
      if (L_USADSTOpen && L_USADSTClose)
      {
         return (true);
      }
      else
      {
         return (false);
      }
   }
   else if (G_BrokerDSTType == 1)
   {
      MqlDateTime specificDayTimeMarch, specificDayTimeOctober;
      int L_lastSundayOfMarch   = 31;
      int L_lastSundayOfOctober = 31;
      specificDayTimeMarch.year   = mqlTime.year;
      specificDayTimeMarch.mon    = 3;
      specificDayTimeOctober.year = mqlTime.year;
      specificDayTimeOctober.mon  = 10;
      for(; L_lastSundayOfMarch > 0; L_lastSundayOfMarch--)
      {
         specificDayTimeMarch.day = L_lastSundayOfMarch;
         TimeToStruct(TimeCurrent(specificDayTimeMarch), specificDayTimeMarch);
         if(specificDayTimeMarch.day_of_week == 0)
         {
            break;
         }
      }
      for(; L_lastSundayOfOctober > 0; L_lastSundayOfOctober--)
      {
         specificDayTimeOctober.day = L_lastSundayOfOctober;
         TimeToStruct(TimeCurrent(specificDayTimeOctober), specificDayTimeOctober);
         if(specificDayTimeOctober.day_of_week == 0)
         {
            break;
         }
      }
      bool L_EUDSTOpen  = mqlTime.mon >  3 || (mqlTime.mon ==  3 && mqlTime.day >= L_lastSundayOfMarch  );
      bool L_EUDSTClose = mqlTime.mon < 10 || (mqlTime.mon == 10 && mqlTime.day <  L_lastSundayOfOctober);
      if (L_EUDSTOpen && L_EUDSTClose)
      {
         return (true);
      }
      else
      {
         return (false);
      }
   }
   else if (G_BrokerDSTType == 2)
   {
      return (true);
   }
   else
   {
      return (false);
   }
}

[chuangmingjijing]

amrali #:
See this, it might help you

https://www.mql5.com/en/code/27860

thank you so much for your code with clarity of thought!

[chuangmingjijing]

Hong Yi Li #:
helpful

thanks a lot . so helpful for me.

Dealing with this problem is difficult for beginners. 

[Hong Yi Li]

chuangmingjijing #:

thanks a lot . so helpful for me.

Dealing with this problem is difficult for beginners. 

I forgot to attach how to apply the function.

I have seen many EAs on the market that do not use the correct calculation method, which results in inaccurate calculated times.

if ( HourTime(Yes, true, 13, 16, AutoDST()) )
{
        YourOpeningFunction();
}

bool HourTime(string P_Type, bool P_Switch, int P_OpenTime, int P_CloseTime, bool P_DST)
{
   MqlDateTime mqlTime;
   TimeToStruct(TimeCurrent(),mqlTime);
   int L_Hour = mqlTime.hour;
   if (!P_Switch)
   {
      return (true);
   }
   else if (P_DST)
   {
      bool L_OpenTime  = (P_OpenTime  + G_BrokerGMTType - 1 + 24) % 24 <= mqlTime.hour;
      bool L_CloseTime = (P_CloseTime + G_BrokerGMTType - 1 + 24) % 24 >= mqlTime.hour;
      if (P_Type == "Yes")
      {
         if (L_OpenTime && L_CloseTime) return (true); else return (false);
      }
      else if (P_Type == "No") 
      {
         if (L_OpenTime && L_CloseTime) return (false); else return (true);
      }
   }
   else
   {
      bool L_OpenTime  = (P_OpenTime  + G_BrokerGMTType - 0 + 24) % 24 <= mqlTime.hour;
      bool L_CloseTime = (P_CloseTime + G_BrokerGMTType - 0 + 24) % 24 >= mqlTime.hour;
      if (P_Type == "Yes")
      {
         if (L_OpenTime && L_CloseTime) return (true); else return (false);
      }
      else if (P_Type == "No") 
      {
         if (L_OpenTime && L_CloseTime) return (false); else return (true);
      }
   }
   Print ("The time function is not set correctly!");
   return (false);
}