Local time zone reporting allows you to run reports in the AdSense account's local time zone. As of v2 of the AdSense Management API, this functionality is enabled by default.
Setting things up
In most cases, all that is required to use local time zone reporting is for the AdSense user to configure their account's local time zone. This allows them to choose a time zone that is more relevant to them, and use it across the AdSense website and AdSense Management API reports.
Requesting a report
The AdSense website and AdSense Management API will use the account's local time zone by default to generate reports. For the AdSense Management API, this choice is controlled via a reportingTimeZone parameter (see ReportingTimeZone) for both ad hoc and saved report generation requests.
To disable local time zone reporting, the reportingTimeZone parameter should be set to GOOGLE_TIME_ZONE; this generates reports using the billing time zone (always America/Los_Angeles).
Note that if the user has never set the local time zone for the account, their account time zone will be considered to be America/Los_Angeles, the same as the billing time zone.
Things to watch out for
Changing time zones
Whenever the time zone for an account is changed, there will be a short transition period of up to two days where the reporting data will potentially be inconsistent. This data will always remain inconsistent, so be careful to note these transition points in your application, if possible.
One particularly relevant example of these transitions is when the local time zone for an account is first set: this will essentially be a switch from the default account time zone to the chosen time zone.