Local time zone reporting allows you to run reports in the AdSense account's local time zone, rather than the default Pacific Time Zone (PTZ).
Setting things up
To use local time zone reporting, the AdSense user must first 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
To request a report in the account's local time zone, all you need to do is set the useTimezoneReporting parameter to true (it defaults to false).
Things to watch out for
The default is PTZ
Even if the user has never set the local time zone for the account, it'll still be possible to request local time zone reports using the AdSense Management API. These will be returned in PTZ, which is the default time zone.
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; reporting defaults to PTZ, so this will essentially be a switch from PTZ to the chosen time zone.
Reports across multiple accounts
If you're making reporting calls across multiple accounts, be warned that all reports will be in PTZ, even if you set useTimezoneReporting to true. This is to avoid any potential inconsistencies caused by having different time zones across the accounts, or different dates at which they were chosen. This behaviour matches the one of the AdSense website.