DateFormater Function...

-(NSString *) dateInFormat:(NSString*) stringFormat {

        char buffer[80];

        const char *format = [stringFormat UTF8String];

        time_t rawtime;

        struct tm * timeinfo;

        time(&rawtime);

        timeinfo = localtime(&rawtime);

        strftime(buffer, 80, format, timeinfo);

        return [NSString  stringWithCString:buffer encoding:NSUTF8StringEncoding];

}

////////Like.......

 NSString *mydate =  [self dateInFormat:@"%Y%m%d-%H%M%S"];