Create organization, create plan, add Quota Policy 1.000.000 requests per ClientApp per month for this plan.
Create API, create Client App, create contract using the plan.
Make a request and inspect the value of X-Quota-Reset HTTP Header in response.
In my case the value in seconds after midnight:
X-Quota-Reset:"86095"
which corresponds to 24 hours.

Observed:
At the nearest midnight the value of X-Quota-Remaining is reset.
The value of X-Quota-Reset is incorrect.

Expected:
X-Quota-Remaining should be reset only next month.