Hi all, check this function for error:

import java.text.SimpleDateFormat;
import java.util.TimeZone;

....

@Configurable("GMT")
    public String GMT = "+0";

....

TimeZone serverTimeZone;
    SimpleDateFormat sdf;

.....

    public void onStart(IContext context) throws JFException {

        this.context = context;
        this.engine = context.getEngine();
        this.history = context.getHistory();
        this.indicators = context.getIndicators();
        this.serverTimeZone = TimeZone.getTimeZone("GMT" + GMT);

.....


if (isValidTime (18, 0, 10, 0))  ... Open Order rules (from 18:00 to 10.00 server time)

   //+--------------------------------------------------------------------------------------------------------------+
   //| isValidTime. Функция проверки торгового канала.
   //| Если время подходит для торговли, функция даёт разрешение на открытие.
   //+--------------------------------------------------------------------------------------------------------------+
        //|  Параметры:
         //|    hb - часы времени начала канала
   //|    mb - минуты времени начала канала
   //|    he - часы времени окончания канала
   //|    me - минуты времени окончания канала
   //+--------------------------------------------------------------------------------------------------------------+
    private boolean isValidTime(int hb, int mb, int he, int me) throws JFException {
    //+--------------------------------------------------------------------------------------------------------------+     
        
        //--- Приводим временной канал к виду String
        String startTime = hb + ":" + mb;
        String endTime = he + ":" + me;
        long tickTime = timeCurrent();
        
        //--- Делаем реплейс
        String parsedStartTime = startTime.replace(":", "");
        String parsedEndTime = endTime.replace(":", "");

        //--- Переводим милисекунды в sdf формат
        String formattedTickTime = sdf.format(tickTime); 
        formattedTickTime = formattedTickTime.replace(":", "");
        //---
        int tickTimeValue = Integer.parseInt(formattedTickTime);
        int startTimeValue = Integer.parseInt(parsedStartTime);
        int endTimeValue = Integer.parseInt(parsedEndTime);
        
        //--- Если время начала меньше времени окончания, то
        if (startTimeValue < endTimeValue){
            if ((tickTimeValue > startTimeValue) && (tickTimeValue < endTimeValue)){
                return true;
            }
        //--- Если же время начала больше времени окончания, то
        } else {
            int tmpTimeValue = startTimeValue;
            startTimeValue = endTimeValue;
            endTimeValue = tmpTimeValue;
            if ((tickTimeValue < startTimeValue) || (tickTimeValue >= endTimeValue)) {
                return true;
            }
        }
        //---
        return false;
    }

    //+--------------------------------------------------------------------------------------------------------------+
    //| timeCurrent. Текущее время в миллисекундах.
    //+--------------------------------------------------------------------------------------------------------------+
    public long timeCurrent() throws JFException{
    //+--------------------------------------------------------------------------------------------------------------+

        return history.getLastTick(instrument).getTime();
    }

This function is true?

There are java libraries that deal with such cases. You can either use SimpleDateFormat or Calendar. For example:

package jforex.test;

import com.dukascopy.api.*;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;

/**
 * The strategy checks on every 10 sec bar if the last tick was within user-defined market hours.
 * Two approaches get used - string operations with Simple data format and use of Calendar.
 *
 */
public class CheckMarketHours implements IStrategy {
   
   private IConsole console;
   private IHistory history;
   
   private Period period = Period.TEN_SECS;
   private Instrument instrument = Instrument.EURUSD;

   private SimpleDateFormat localSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    
   private SimpleDateFormat gmtSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   
   @Override
   public void onStart(IContext context) throws JFException {
      console = context.getConsole();
      history = context.getHistory();

      gmtSdf.setTimeZone(TimeZone.getTimeZone("GMT"));
   }
   
   //use of string operations
   private boolean isValidTimeFromSdf(int fromHour, int fromMin, int toHour, int toMin) throws JFException {         

      long lastTickTime = history.getLastTick(instrument).getTime();
      //you want to work with the date of the last tick - in a case you are back-testing
      String fromStr = localSdf.format(lastTickTime).substring(0, 11) + String.valueOf(fromHour)+":"+String.valueOf(fromMin) + ":00";
      String toStr = localSdf.format(lastTickTime).substring(0, 11) + String.valueOf(toHour)+":"+String.valueOf(toMin) + ":00";
      try {
         long from = localSdf.parse(fromStr).getTime();
         long to = localSdf.parse(toStr).getTime();
         
         print("sdf: " + gmtSdf.format(from) + " - " + gmtSdf.format(to) + " last tick: " + gmtSdf.format(lastTickTime));
         return lastTickTime > from  && lastTickTime < to;
         
      } catch (ParseException e) {
         e.printStackTrace();
      }
      
      return false;
   }
   
   //use of calendar
   private boolean isValidTimeFromCalendar(int fromHour, int fromMin, int toHour, int toMin) throws JFException {
      
      long lastTickTime = history.getLastTick(instrument).getTime();
      Calendar calendar = Calendar.getInstance();
      //you want to work with the date of the last tick - in a case you are back-testing
      calendar.setTimeInMillis(lastTickTime);
      calendar.set(Calendar.HOUR, fromHour);
      calendar.set(Calendar.MINUTE, fromMin);
      calendar.set(Calendar.SECOND, 0);
      long from = calendar.getTimeInMillis();
      
      calendar.setTimeInMillis(lastTickTime);
      calendar.set(Calendar.HOUR, toHour);
      calendar.set(Calendar.MINUTE, toMin);
      calendar.set(Calendar.SECOND, 0);
      long to = calendar.getTimeInMillis();
      
      print("calendar: " + gmtSdf.format(from) + " - " + gmtSdf.format(to) + " last tick: " + gmtSdf.format(lastTickTime));
      
      return lastTickTime > from  && lastTickTime < to;
   }



   @Override
   public void onBar(Instrument instrument, Period period, IBar askBar, IBar bidBar) throws JFException {
      if (period != this.period || instrument != this.instrument)
         return;

      print ( "Is valid time? SimpleDateFormat: " + isValidTimeFromSdf (10, 0, 18, 0) + ". Calendar: " + isValidTimeFromCalendar(10, 0, 18, 0));
   }

   private void print(Object o) {
      console.getOut().println(o);
   }

   @Override
   public void onTick(Instrument instrument, ITick tick) throws JFException {   }
   @Override
   public void onMessage(IMessage message) throws JFException {   }
   @Override
   public void onAccount(IAccount account) throws JFException {   }
   @Override
   public void onStop() throws JFException {   }

}

If i set isValidTimeFromCalendar (10, 0, 12, 0) expert open order in time interval from 7:00 to 9:00.

Why? This function use server or local time (time from my pc)? I need server dukascopy time.

Because the method assumes that you pass the local time to it.
Consider the following adjusted strategy:
viewtopic.php?f=31&t=42386

Thanks for help! Realy, this new function is work on server time.