BarPeriod

Type:

BarOffset

BarZone

TimeFrame

FrameOffset

Type:

Remarks:

• Use the bar function for special bars that are not bound to a certain bar period.
• BarPeriod can be set to any value between 0.00166 and 1440 in the script. Bar periods above 1 are rounded to a multiple of minutes. The [Period] slider moves in fixed steps corresponding to the usual bar periods of trading platforms; directly setting BarPeriod places the slider at the position closest to the BarPeriod value. If BarPeriod is set directly in the script, the slider can not be moved.
• In [Test] mode, bar generation is based on the UTC time stamps of the historical price data. For M1 data it is supposed that the time stamps indicate the end (not the start) of a tick. Otherwise use the TickFix variable for adjusting M1 data with different time stamps. In [Trade] mode, bar generation is based on UTC time from the PC clock, not on the broker's server time for avoiding sync problems by connection interruptions and Internet lag.
• On bar periods less than ~ 10 minutes, setting the TICKS flag and using high resolution .t1 price data is recommended for backtesting. It's mandatory on bar periods of less than a minute. For this set History to ".t1" and BarPeriod to the number of seconds divided by 60, f.i. BarPeriod = 5./60. for 5 seconds. Mind the decimal; 5/60 would be considered an int and thus evaluate to 0. For extremely short bar periods, make sure that TickTime is always less than a bar period.
• For bar periods longer than a day, set BarPeriod = 1440 and use TimeFrame for setting up weekly or monthly time periods. A week can contain 5, 6, or 7 trading days dependent on the Weekend setting.
• BarPeriod, BarOffset, and BarZone affect the sampling of the price data; therefore they must be set in the first run before any asset() call, can not change afterwards, and can not be optimized in WFO mode. TimeFrame, FrameOffset, and AssetZone can be set anytime and can be optimized without restrictions.
• If BarOffset is 0, bars begin and end at day/hour boundaries. This has the consequence that daily bars would begin and end at 00:00 midnight, so their OHLC candles contain the prices from the previous, not from the current day. For preventing this, BarOffset has a default value of 1000 (equivalent to 4:40 pm) on daily bars. Make sure to set BarOffset accordingly so that the bar ends just at the time when the script trades. Example for trading at 16:25: BarOffset = 60*16+25;.
• All time zone settings (BarZone, AssetMarket etc.) assume UTC time for price history. If price history is already in local time, which is often the case for EOD history, either convert it to UTC or don't use time zone settings in the back test.
  

TimeFrame vs. BarPeriod:

• TimeFrame is not equivalent to BarPeriod. A script with BarPeriod 60 and TimeFrame 1 is not the same as a script with BarPeriod 1 and TimeFrame 60, due to subtle differences listed below. If multiple time frames or different trade time offsets are not required, set the time frame with BarPeriod only. This uses the lowest possible number of bars and results in the highest speed for testing and training. 
• Barperiod affects only the bar chart and the frequency of the run function, while TimeFrame determines the price functions, the shifting of series, and the bar at which advise and trade calls are executed.
• Trades entered in the run function are not executed when the TimeFrame has not ended, but trade entry/exit conditions are tested at the end of every bar period.
• Any calculations in the run function are executed at any bar period, unless they are explicitely restricted to time frames. Use the frame function for this if needed.
• Beginning and ending at day/hour boundaries is guaranteed for BarPeriod, but not for TimeFrame due to the different number of bars per day when holidays or weekends lie in the simulation period. For letting a time frame start at always the same hour, use the hour() or lhour() functions. For aligning daily time frames to a certain hour or time zone, either set TimeFrame by script to the negative number of day bars at midnight (see example) and to 0 otherwise, or use the AssetFrame variable, or use the frameSync() function.
• Use BarPeriod = 1440 and TimeFrame = framesync(7) for weekly time frames. The week begin can be set with FrameOffset; otherwise the week begins on Monday.
• TimeFrame has no effect on variables in bar period units, f.i. LookBack, LifeTime, or WaitTime. For extending those time periods, multiply the variable value with the number of bars per time frame.
• TimeFrame does not affect a few indicators that do not use a Data series, but directly the current asset price series. This is mentioned in the description of the indicator.

Examples:

#define H24 (1440/BarPeriod)
#define H4 (240/BarPeriod)
#define H1 (60/BarPeriod)
... 
BarPeriod = 60; // 1 hour (60 minutes) bars
...
// create a 4-hour price series ///////////////////////////////////
TimeFrame = H4;
vars PriceH4 = series(price());
 

// create a 24-hour price series /////////////////////////////////
TimeFrame = H24;
vars PriceH24 = series(price());

// skip bars outside market hours (equivalent to AssetMarket) //////
// equivalent to AssetZone
static int SkippedBars = 0;
if(!market(ET,0)) {
   TimeFrame = 0;
   SkippedBars--; // count negative number of bars outside market hours
} else if(TimeFrame == 0) {
   TimeFrame = SkippedBars;
   SkippedBars = 0;
} else
  TimeFrame = 1;
vars PriceInMarketHours = series(price());

// create a daily price series (equivalent to AssetZone) ////////
static int BarsPerDay = 0;
if(hour(0) < hour(1)) { // day change  
  TimeFrame = BarsPerDay; // end the frame
  BarsPerDay = 0;
} else {
  TimeFrame = 0; // inside the frame
  BarsPerDay--;  // count negative number of bars per day
}
vars PriceD1 = series(price());

// alternative: a midnight-aligned price series using frameSync()
StartWeek = 10000;
TimeFrame = frameSync(H24);
vars PriceD1 = series(price());

// back to 1-hour time frames
TimeFrame = 1;					
...

See also: