Period for specific time and range

[tesths]

#81 has already claim this but I want to show my user case.

I use web crawler save some data and I make a website with this data.(This data is about weather.)
And this data is refresh every hour at 28 minute. (like 00:28, 01:28, 02:28). And I want provide api for this data.

I use token to verify the user. Due to the data refresh time, I want to limit the request time every hour in this hour 28 minute to next hour 28 minute.( Like 00:29-01:29 request only 10 times. 01:29-02:29 request only 10 times)

I read the document about rack-attack and the issue about #113 . And I think the best plan now is make a task scheduler and clear the cache every hour. I think it's not a very good choice.

Though it's a real not generally useful and rack-attack design for evil request. But I think may a lot of people use rack-attack to limit api request times. And period ranges is really useful.