Date and Time

The online trading system MetaTrader 4 uses the indications of two time sources - the local (PC) time and the server time.

Local time - the time that is set on the local PC.

Server time - the time that is set on the server.

TimeLocal() Function

datetime TimeLocal()

The function returns the local PC time expressed in the number of seconds lapsed since 00:00 of the 1st of January 1970. Note: At testing, the local time is modeled and coincides with the modeled last-known server time.

A large majority of events that take place in the client terminal are considered with accordance to the server time. The time of tick coming, new bar beginning, order opening and closing is considered with accordance to the server time. To get the value of the server time that corresponds with the current time, the TimeCurrent() function should be used:

TimeCurrent() Function

datetime TimeCurrent()

The function returns the last known value of the server time (the time of the last quote coming) expressed in seconds lapsed since 00:00 of the 1st of January 1970. The client terminal updates the time of the last quote coming (together with other environment variables) before launching special functions for execution. Each tick is characterized with its own value of the server time that can be obtained using the TimeCurrent() function. During the execution, this value can only be changed as a result of the RefreshRates() function call and only if the information has been updated since the last execution of the RefreshRates() function, i.e., in case the new values of some environment variables have come from the server.

The time of bar opening, Time[i], does not coincide with the time of new tick coming, as a rule. The time of any timeframe bar opening is always divisible by the timeframe. Any first tick appeared within a timeframe is bar-forming; if there is no tick receipt within a timeframe, the bar will not be formed within the timeframe.

For example, the tick coming to the terminal at time (server) t0 results in forming a bar with the time opening equal to Time[i+2] (Fig. 143). The moment specified as the beginning of the timeframe does not concur with moment t0, though it can accidentally concur with it, in general. The subsequent ticks that come to the terminal within the same timeframe (at the moments of t1 and t2) can change the parameters of the bar, for example, maximum price or open price, but they do not affect the time of bar opening. The bar closing time is not considered in the online trading system MetaTrader 4 (formally, the time of the last tick coming within a timeframe or the beginning time of the next timeframe can be considered as the bar closing time, as shown in Fig. 143).

Fig. 143. Bar forming sequence in the online trading platform MetaTrader 4.

It is shown in Fig. 143 that it is possible that bars are not formed at some time periods that are equal to the timeframe. Thus, between time t5 of the tick coming and t6 of the next tick coming, the full timeframe is packed, so the new bar hasn't been formed at that time period. In this manner, the time of bar opening may differ from the time of opening of an adjacent bar by more than a whole timeframe, but it is always divisible by a timeframe. To demonstrate the sequence of bar forming, we can use the EA timebars.mq4 that outputs the time of tick coming and the time of bar opening:

//--------------------------------------------------------------------
// timebars.mq4
// The program is intended to be used as an example in MQL4 Tutorial.
//--------------------------------------------------------------------
int start()                            // Spec. function start()
  {
   Alert("TimeCurrent=",TimeToStr(TimeCurrent(),TIME_SECONDS),
         " Time[0]=",TimeToStr(Time[0],TIME_SECONDS));
   return;                             // Exit start()
  }
//--------------------------------------------------------------------

The results of the EA timebars.mq4 working are shown in Fig. 144. It is obvious that the first tick at the regular time period of 1 minute duration came at 14:29:12, at the same time a new bar was formed with the opening time - 14:29:00. Please note that the right column of the message box displays the server time, the left column displays the local time.

Fig. 144. Bar forming sequence in the online trading system MetaTrader 4.

In case the ticks come rarely (for example, the period between the end of the European session and the beginning of the Asian session), you can observe another phenomenon during the execution of timebars.mq4: the opening time of the adjacent bars can differ from each other by more than 1 minute (for one-minute timeframe). At the same time, the indexing of bars is saved in succession, without spaces.

The server time of servers in different dealing centers may vary. The time of beginning and finishing trades is set on each server individually and it can disagree with the begining and the end of the regular day. Some dealing centers, for example, have the settings that perform trade opening on Sunday at 23:00 of server time. This results in forming of incomplete daily bars, their practical duration is equal to one hour (Fig. 145).

Fig. 145. Different bar history in different dealing centers.

The usage of date and time functions is rather easy in MQL4. Some of them transform the server and the local time in seconds lapsed since 00:00 of the 1st of January 1970 into an integer number that corresponds with an hour, a day, etc. Other functions return an integer number that corresponds with the current hour, day, minute, etc.

TimeSeconds (), TimeMinute(), TimeHour(), TimeDay(), TimeMonth(), TimeYear(), TimeDayOfWeek () and TimeDayOfYear() Functions

This is a group of functions that return the number of seconds lapsed from the beginning of the minute, or minute, hour, day, month, year, day of week and day of year for the specified time. For example:

int TimeMinute(datetime time)

The function returns minutes for the specified time.

Parameters:

time - the date expressed in number of seconds that lapsed since 00:00 of the 1st of January 1970.

int TimeDayOfWeek(datetime time)

This function returns the day of week (0-Sunday,1,2,3,4,5,6) for the specified date.

Parameters:

time - the date expressed in number of seconds that lapsed since 00:00 of the 1st of January 1970.

The considered functions can be used for analysis of any bar opening time, for example. The EA named bigbars.mq4 intended for finding bars of a size that is not less than specified size is shown below.

//--------------------------------------------------------------------
// bigbars.mq4
// The code should be used for educational purpose only.
//--------------------------------------------------------------- 1 --
extern int Quant_Pt=20;                // Number of points
//--------------------------------------------------------------- 2 --
int start()                            // Spec. function start()
  {
   int H_L=0;                          // Height of the bar
   for(int i=0; H_L<Quant_Pt; i++)     // Cycle for bars
     {
      H_L=MathAbs(High[i]-Low[i])/Point;//Height of the bar
      if (H_L>=Quant_Pt)               // if the high bar is not found
        {
         int YY=TimeYear(  Time[i]);   // Year
         int MN=TimeMonth( Time[i]);   // Month         
         int DD=TimeDay(   Time[i]);   // Day
         int HH=TimeHour(  Time[i]);   // Hour         
         int MM=TimeMinute(Time[i]);   // Minute
         Comment("The last price movement more than ",Quant_Pt,//Message
         " pt happened ", DD,".",MN,".",YY," ",HH,":",MM);//output
        }
     }
   return;                             // Exit start()
  }
//--------------------------------------------------------------- 3 --

The bigbars.mq4 EA searches the nearest bar whose height (difference between minimum and maximum) is more than or equal to the value specified in the external variable Quant_Pt. The date and time of the found bar are outputted to the window of financial instrument by the Comment() function.

Seconds (), Minute(), Hour(), Day(), TimeMonth(), TimeYear(), DayOfWeek () and DayOfYear() Functions

This is the group of functions that return the current second, minute, hour, day, month, year, day of week and day of year for the last known server time. The last known server time is the server time that corresponds with the moment of the program launch (launch of any special function by the client terminal). The server time is not changed during the execution of the special function.

int Hour()

It returns the current hour (0,1,2,..23) of the last known server time. Note that the last known server time is modeled during testing.

int DayOfYear()

It returns the current day of the year (1 is the 1st of January,..,365(6) is the 31st of December), i.e., the day of the year of the last known server time. Note that the last known server time is modeled during testing.

The EA timeevents.mq4 that performs some actions as soon as the specified time comes can be used as an example of usage of the above functions.

//--------------------------------------------------------------------
// timeevents.mq4
// The code should be used for educational purpose only.
//--------------------------------------------------------------- 1 --
extern double Time_Cls=16.10;          // Orders closing time
bool Flag_Time=false;                  // Flag, there are no messages yet
//--------------------------------------------------------------- 2 --
int start()                            // Spec. start function
  {
   int    Cur_Hour=Hour();             // Server time in hours
   double Cur_Min =Minute();           // Server time in minutes
   double Cur_time=Cur_Hour + Cur_Min100; // Current time
   Alert(Cur_time);
   if (Cur_time>=Time_Cls)             // If the time for the event has come
      Executor();                      //.. then perform devised actions
   return;                             // Exit from start()
  }
//--------------------------------------------------------------- 3 --
int Executor()                         // User-defined function
  {
   if (Flag_Time==false)               // If there are no messages yet
     {                                 // .. then report (1 time)
      Alert("Important news time. Close orders.");
      Flag_Time=true;                  // Now the message has already appeared
     }
   return;                             // Exit user-defined function
  }
//--------------------------------------------------------------- 4 --

The server time is calculated in hours and minutes during the execution of the special function start() (blocks 2-3). The line:

   double Cur_time = Cur_Hour + Cur_Min100; // Current time

represents the current server time expressed as the real variable Cur_time. The use of real variables is convenient in comparison operations:

   if (Cur_time >= Time_Cls)           // If the time for the event has come

If the current time is more than or equal to the value of Time_Cls specified by user, then the Executor() user-defined function will be called for execution. In this example, the user-defined function puts out a message with trading recommendations. In general, this function may contain any code, for example, make trades, send e-mails, create graphical objects, etc.

Functions of Date and Time

To get the detailed information about these and other functions, refer to the Documentation at MQL4.community, at MetaQuotes Ltd. website or at the "Help" section of MetaEditor.