107int ReferenceUtcOffsetMinutes(const datetime utc)108{109   MqlDateTime date;110   if (!TimeToStruct(utc, date))111      return 120;112   MqlDateTime transition = {};113   transition.year = date.year;114   transition.mon = 3;115   transition.day = 1;116   transition.hour = 7;117   datetime marchFirst = StructToTime(transition);118   TimeToStruct(marchFirst, transition);119   datetime summerStart = marchFirst + ((7 - transition.day_of_week) % 7 + 7) * 86400;120121   transition.mon = 11;122   transition.day = 1;123   transition.hour = 6;124   datetime novemberFirst = StructToTime(transition);125   TimeToStruct(novemberFirst, transition);126   datetime summerEnd = novemberFirst + (7 - transition.day_of_week) % 7 * 86400;127   return utc >= summerStart && utc < summerEnd ? 180 : 120;128}129// Ordinary charts align broker time to the strategy reference; tester time is unchanged.130void RefreshClock(bool force = false)131{132   datetime now = TimeCurrent();133   if (MQLInfoInteger(MQL_TESTER))134   {135      clockOffsetMinutes = 0;136      clockValid = true;137      clockChecked = now;138      return;139   }140   if (!force && clockChecked > 0 && MathAbs((double)(now - clockChecked)) < 60)141      return;142   clockChecked = now;143   datetime utc = TimeGMT();144   clockValid = false;145   if (now <= 0 || utc <= 0)146      return;147   int observed = (int)MathRound((double)(now - utc) / 60);148   int snapped = observed < 0 ? -(((-observed + 7) / 15) * 15) : ((observed + 7) / 15) * 15;149   if (MathAbs(observed - snapped) > 3 || snapped < -720 || snapped > 840)150      return;151   int reference = ReferenceUtcOffsetMinutes(utc);152   int offset = snapped - reference;153   if (offset < -720)154      return;155   clockOffsetMinutes = offset;156   clockValid = true;