I just finished watching this drama. It's three in the morning and I don't know what to do with myself.
I liked it a lot.
I haven't watched Leap day (I might watch it in the future) because it didn't interest me as much as this drama, 940920 is good even without watching the prequel.
I pierced the story about Yeesa while watching, it was not complicated to figure out so I wasn't really confused about anything.

Story
I love time travel stories and this one was awesome. It has set rules and the way it works makes sense. It's not overly complicated and we as watchers find out information with the characters which is fun. I actually managed to figure out a lot of things that are going to happen or how time travel works.
This drama made me think a lot about the characters and the way the story is going.

I wanted to give this drama a ten but I can't because of the ending. It's not bad, it's actually satisfying but I wanted more.
The stories of two characters I liked the most were left unfinished. That made me sad and mad because I hoped some miracle would happen and they would have a happy ending.

Also, I don't like when we follow some characters, they suffer, we get emotionally invested and then they don't get the happy ending they deserve but some people who look like them or are them from another universe get a happy ending and we are supposed to feel happy.
I'm not happy. That's my pet peeve in dramas, I want original characters to get happiness, not another version of them. It's not the same.
Rant over.

Things I liked:
- The way time travel works and how everything is connected.
- The question of memories, the fact that we are made of our memories. We know we exist because of them. They make us who we are so what are we without them?
- All of the characters and their individual stories.
- Co Ying and Ka Chung are smart (not all the time but most of their decisions are smart, they never made me feel frustrated).
- The subtle romance between Ka Chung and Co Ying, the way their friendship was growing and how they trusted each other.
- The villain. That's what happens when a bad person gets access to time travel but I guess there would be no drama if he wasn't like that.
- Every episode is exciting (episodes mostly end on cliffhanger so you have to watch the next one).

Overall, it's an awesome story that will make you think a lot. I totally recommend it.