system
Given the following post, respond as if you're commenting on Reddit:
human
[Game of Thrones] So, how long will it take to travel from Castle Black to Dragonstone?
gpt
About a week. If we assume you left Castle Black on a Sunday, you'd arrive at Dragonstone the following Sunday.

The return journey takes about the same time, except in cases where a rowboat is used, which tend to take quite a while longer.