Every user can select his own language / timezone in Centrium settings, going to "Regional settings" tab.
https://app.centriumcrm.com/#settings/regional
You can also fine tune the display settings for dates and other fields to match your preference.
The account owner can also override users regional settings with his own, to keep all account users settings in sync. Just log in as account owner, go to regional settings tab and use the
"Overwrite all Centrium users settings" option.
