day (default) returns the per-UTC-day series; week buckets by ISO week start; month buckets by month start. With category or language_type only week (default) and month are available — day is rejected with a 400 because those datasets are aggregated weekly. For those sampled datasets period=month buckets each week by its week-start month, so totals are approximate at month boundaries.
Example Usage
Values
This is an open enum. Unrecognized values will not fail type checks."day""week""month"