yes, you should sure you have earlier time periods (30M, 15M, 5M)'s data, and used those data to calculat buy/sell signals.
I assume that you mean shorter timeframe not earlier, see the example below "int timeframe" allows you to specify a time frame(longer or shorter) than that of the chart to which the ea is attached to, this is typical of many if not most of the indicators in MT4.( "0" defaults to current chart time frame.)
ah that obvious? doh! cheers