Getting 429 with huge `Retry-After` numbers

[Larry-Person]

Over the past week I've been getting 429 rejections (exceeded rate limit) with `Retry-After` values up to around 12 hours. I continue to get 429s for that entire interval with the `Retry-After` declining steadily, but it takes the original amount of time until I no longer get a 429. (For example, if the value was 43200, after 12 hours I stop getting 429s and can use the API normally.) I'm surprised because I've refactored my application to make drastically fewer API calls than I was before (l was able to eliminate over 90% of the API calls!).

This seems to happen over night in the eastern time zone in the US. At least when I've seen it happen it started. 

Tonight at 05:37 UTC I got a 429 with `Retry-After` of 31566. At 06:59 UTC I got one with `Retry-After` of 26640.

Is this a system-wide issue or am I doing something to warrant 12 hours of throttling?