All reports and alerts are generated based on the localization (timezone) settings of the logged in user.

If your account has a multi-user login this means that different users will have different times everywhere in Pingdom, from reports to alerts.

So there are basically 2 scenarios:

1. You have one account that you log in to. This account was set up to use GMT on account creation. All reports and alerts will come in GMT. To change this, you change the Localization settings of the account.
   
   
2. The main account has multi-user access, which means each invited User have their own localization settings that affect the alerts they receive.
   
   Example:

You have one main account with invited users, the main account is in GMT. Logging in to the main account will give reports and alerts in GMT.

A user is invited to this account and specifies CET when their account is created, this user logs in and views report from the main account, these are now displayed in CET. The same thing for alerts.

A second user is invited, this user is all the way on the west coast in the United States and thus sets the account to use PST, the same reports and alerts from above are displayed in PST to this user.

In short, it is dependent on the individual user settings.

Here is a guide on how to change the localization (timezone) settings in an account.