求翻译：因为加拿大冬季气候和香港比太寒冷， 我们的儿子在香港工作， 我们也想去看看他，所以购买票时准备Nov 21 2011 回香港， 我们来加拿大的日期在 Apr 2012.是什么意思？

Because Canada and Hong Kong than too cold climate in winter, our son is working in Hong Kong, we also want to see him, so when buying tickets for Nov 21 2011 back to Hong Kong, we come to Canada in Apr 2012 date.