What does this do? iBarShift

Hi i am new to meta trader and ea. I need some help in writing some code if that is ok.

I was wondering what this exactly does. I read the help files on it telling me "The function returns bar shift with the open time specified" but what is the shift?

Does it return a number for the position it gets from the time?

int Begin = iBarShift(NULL,0,TimeBegin);

TimeBegin is a datatime.

Can someone please send a reply on this problem?

Thanks

int iBarShift(string symbol, int timeframe, datetime time, bool exact=false)Search for bar by open time. The function returns bar shift with the open time specified. If the bar having the specified open time is missing, the function will return -1 or the nearest bar shift depending on the exact.

Parameters:
symbol - Symbol the data of which should be used to calculate indicator. NULL means the current symbol.timeframe - Timeframe. It can be any of Timeframe enumeration values. 0 means the current chart timeframe.time - value to find (bar's open time).exact - Return mode when bar not found. false - iBarShift returns nearest. true - iBarShift returns -1.
Sample:
datetime some_time=D'2004.03.21 12:00'; int shift=iBarShift("EUROUSD",PERIOD_M1,some_time); Print("shift of bar with open time ",TimeToStr(some_time)," is ",shift);
so, if you are looking for the shift of the bar located at a specific date and time it will return the integer value for that bar.