This is how my MetaTrader Expert Advisor framework formed throughout 2013. I found myself storing much information into variables and would then recalibrate those variables depending upon fixed time periods.

metatrader-ea-framework.mq4

//+------------------------------------------------------------------+
//| MetaTrader EA Framework.mq4
//| Copyright 2013, Ryan Sheehy
//| http://www.currencysecrets.com
//+------------------------------------------------------------------+
#property copyright "Copyright 2013, Ryan Sheehy"
#property link      "http://www.currencysecrets.com"

//--- global variables (keep capitalised)
string VERSION = "1.0.0";

//--- global time variables - needs to correspond to
//--- every different type of time period you use, eg.
// datetime NOWM1, NOWH1, NOWH4, NOWD1, NOWW1; 

//--- global gate variables that store double values, eg.
// double GATE_VOLT, GATE_OPEN, GATE_DRAWDOWN;

//--- global gate variables that store integer values, eg.
// int GATE_TREND;

//--- global gate variables that store boolean values, eg.
// bool GATE_ACTIVE, GATE_TRADE_DATE;

//--- global input parameters, eg.
// extern int EXT_BARS = 60;
// extern double EXT_ATR_MULTIPLIER = 2.5;

//+------------------------------------------------------------------+
//| expert initialization function                                   |
//+------------------------------------------------------------------+
int init()
{
	string sym = Symbol();
	//--- run functions for GATE variables and have them
	//--- store their data into their variables, eg.
	// GATE_TREND = getTrend( sym ); 
	
   return(0);
}
//+------------------------------------------------------------------+
//| expert deinitialization function                                 |
//+------------------------------------------------------------------+
int deinit()
{
	string sym = Symbol();
	//--- run functions to alert of deactivation of EA
	//--- from this symbol, eg.
	// alertMe( "DEINIT for " + sym );
  
   return(0);
}
//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
int start()
{
//----
	datetime t;
	string sym = Symbol();
	//--- run this function every tick
	if ( Bid > 0 ) {
		doPerTick( sym );
	}

	//--- run this function every 1 minute
	t = iTime( sym, PERIOD_M1, 0 );
	if ( NOWM1 != t ) {
		doPerMinute( sym, PERIOD_M1 );
		NOWM1 = t;
	}

	//--- run this function every 1 hour
	t = iTime( sym, PERIOD_H1, 0 );
	if ( NOWH1 != t ) {
		doPerHour( sym, PERIOD_H1 );
		NOWH1 = t;
	}

	//--- run this function every 4 hours
	t = iTime( sym, PERIOD_H4, 0 );
	if ( NOWH4 != t ) {
		doPerHour( sym, PERIOD_H4 );
		NOWH4 = t;
	}

	//--- run this function every day
	t = iTime( sym, PERIOD_D1, 0 );
	if ( NOWD1 != t ) {
		doPerDay( sym, PERIOD_D1 );
		NOWD1 = t;
	}

	//--- run this function every week
	t = iTime( sym, PERIOD_W1, 0 );
	if ( NOWW1 != t ) {
		doPerWeek( sym, PERIOD_W1 );
		NOWW1 = t;
	}

   return(0);
}
//+------------------------------------------------------------------+


void doPerTick( string sym ) {

}

void doPerMinute( string sym, int per ) {

}

void doPerHour( string sym, int per ) {
	if ( per == PERIOD_H1 ) {

	} else if ( per == PERIOD_H4 ) {

	}
}

void doPerDay( string sym, int per ) {
	
}

void doPerWeek( string sym, int per ) {
	
}