You can control the timezone in which Analytics Reports are calculated in Analytics Settings (Analytics --> Dashboard --> Click Analytics Settings in the top right corner).
The time zone set is reflected in the timestamp at the bottom of each report. This timezone is a site-wide configuration which affects how all others who log into Recurly see the Analytics.
To update the timezone for your exports specifically, you and any other users who download exports will need to update your personal timezones. To do this, click on your name in the top right corner of the screen -- > Click Edit Personal Info --> Update your timezone --> Save Changes. Once this is done, you will see all export data process in your chosen personal timezone.