
the ancient time is just moving slowly compared to the modern time or it could be that the modern time is moving faster than the ancient time. so that you won't get confused, just make a comparison, for example: 1 day in modern time is equal to 1 month in ancient time. so if Tong spent a year in the ancient time, only 12 days would have passed in the modern time.

omg you're right! I forgot about that! Now I have a new theory... since Tong is originally from the modern time, did that flip the flow of time when she got to the ancient time? omg this is messing with my head more... I suppose there should be an explanation for this, i'd hate it if this was a plot hole.
I know theres a time slip but how come the sister said "your back already?" And "is it suppose to be 2 months?" I thought its slower in ancient time and faster in modern time