MT5 Session Overlap Trading Windows

Detecting session overlaps in MetaTrader 5 requires reliable hour extraction. The deprecated TimeHour(datetime) function should be replaced with TimeToStruct for modern builds.

Modern hour extraction

Instead of the deprecated call:

// Deprecated — do not use on modern builds
int hour = TimeHour(now);

Use the current standard:

datetime now = TimeCurrent();
MqlDateTime dt;
TimeToStruct(now, dt);
int hour = dt.hour;

Safe modulo handling for hour inputs

When calculating offsets or accepting user-defined hours, always wrap to the valid 0–23 range:

int offset = -5;  // example negative shift
int targetHour = ((hour + offset) % 24 + 24) % 24;  // Always 0–23

This handles negative values correctly, which is common when shifting across midnight.

Session overlap detector

//+------------------------------------------------------------------+
//| Session Overlap Detector                                         |
//+------------------------------------------------------------------+
bool IsOverlapSession(int londonStart, int londonEnd,
                      int nyStart, int nyEnd)
  {
   datetime now = TimeCurrent();
   MqlDateTime dt;
   TimeToStruct(now, dt);
   int h = dt.hour;
   
   int ls = ((londonStart % 24) + 24) % 24;
   int le = ((londonEnd % 24) + 24) % 24;
   int ns = ((nyStart % 24) + 24) % 24;
   int ne = ((nyEnd % 24) + 24) % 24;
   
   bool londonActive = (ls < le) ? (h >= ls && h < le)
                                 : (h >= ls || h < le);
   bool nyActive     = (ns < ne) ? (h >= ns && h < ne)
                                 : (h >= ns || h < ne);
   
   return londonActive && nyActive;
  }

This pattern keeps your educational code copy-paste valid on current MetaTrader 5 builds.