Relative dates All Core API and MCF Reporting API queries previously required a start and end date. In the past, apps that displayed recent data - like the last 14 days - would have to manually determine today’s date, determine when 14 days ago was, and format the dates so they could be used.
Sample size control In certain cases, data may be sampled. To simplify setting and reporting the impact of sampling, we’ve added a couple new sampling related features.
First, we added a new query parameter to set the level of sampling. Developers can now specify whether reports should be faster or be more precise.
Second, we added 2 new fields to the API response:
sampleSize - The number of samples that were used for the sampled query. sampleSpace - The total sampling space size. This indicates the total available sample space size from which the samples were selected.