When your account is newly created default time zone will be GMT (00:00) or it will be assigned based on the country you are registering from. In order to change time zone settings in your account, sign in to your MailGoes account and click on Edit Profile option from the menu or you can access the same from top-right of the page. Select preferred time zone you want to set and submit the page. Please make sure that changing this option reflects everywhere including Reports, Campaign Schedules...