If you've ever seen 'Supernatural' there is an episode in which Sam's day is repeating over and over again and he has to deal with his brother's death. He tries to save his brother many times but without any result. I've seen 12 seasons of the series but this episode will always be my favourite one. And that was pretty much the reason why I watched this movie, because it reminded me of that SPN episode.

Gladly, I wasn't disappointed. It was a good movie, one of the best korean movies I've seen so far.

The story keeps you interested til the very end, it's very well-written and well-developed. I usually predict the plot-twists easily but the plot twist in 'A day' surprised me. I seriously didn't expect that.
There's no much to say about the characters since the storyline was more important here, so we couldn't see much of the main leads. But it's understandable, since it's a thriller.
Why am I giving it just an 8 insted of 10? Well, because some parts were kind of boring.

The cast was awesome, I loved it.

I recommend this movie to everyone. It's worth your time and you won't regret watching it.