在国庆期间的英文是：During the National Day 。
最简单的就是during the National holiday. 如果用在句首表示（因为）在国庆期间，会怎么怎么样，就直接用Due to the national holiday，如：在国庆期间，我们公司不营业： Due to the national holiday. our office is closed.
双语例句
1，在国庆期间，我们去了古根海博物馆。
We went to Guggenheim Museum during the National Day.
2，在国庆期间，大多数人会放几天假。
Most people will have a few days off.
3，据了解，此广告在国庆期间开始投放于全国各大机场，获得了热烈的反响。
To understand that this advertisement in National Day period begins to put in each big airport, obtain the warm echo.
4，截止到周三为止，中国电影票房在国庆期间获得了18.5亿元（2亿9100万美元）的票房收入，这也创造了同期历史最高记录。
China's box office rang up takings of 1.85 billion yuan ( about 291 million U.S.dollars) during the National Day holiday, which ended on Wednesday, a record high.
5，从这我们可以看出，在国庆期间，数码相机的价格水平还是比较稳定的，没有大起大落的现象发生，给我们提供了一个比较好的购买时机。
From this we can see in the National Day period, digital camera prices relatively stmable, there is no big ups and downs of the phenomenon，has provided us with a better time to buy.