import java.text.SimpleDateFormat;
import java.util.GregorianCalendar;

df=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
starttime=new GregorianCalendar();
endtime=new GregorianCalendar();
buildEnd=new GregorianCalendar();

//------- look here -------
starttime.setTime(df.parse("2008-5-10 10:10:10"));
endtime.setTime(df.parse("2008-5-10 11:10:10"));
//------- user settings end -----

for (hudson.model.AbstractProject p : hudson.model.Hudson.instance.projects) {
    for (hudson.model.AbstractBuild b : p.getBuilds() ) {
        if (b==null) break; //I think that can't be null anyway
        if ( b.isBuilding() || b.timestamp.compareTo(endtime) >= 0 ) continue;
        buildEnd.setTimeInMillis(b.timestamp.getTimeInMillis()+b.duration);
        if ( buildEnd.compareTo(starttime) < 0 ) break;

        println b;
    }
}