我想大家可以查查 Practical English Usage,有明确的时间的未来式,其实最好是用 is going to...
例如
I'm going to fly to Sydney tonight.(正确)
I will fly to Sydney tonight.(不好)
而第二句回覆的 He'll be flying...(tonight),是明显错误了.这种情况没有可能使用 future continuous tense 的.
正确的翻译,愚以为是:
Today is the last day for my cousin to visit his family,he's going to fly to Australia and study there tonight.