If you're the team owner or admin you'll be able to edit your Team's details.
From the app:
Open the TeamLinkt App
Click the Gear Icon in the top right to open your Team Settings
Click 'Edit Team'
Select Your timezone
From the Web:
Log into your TeamLinkt Account at app.teamlinkt.com
Go to the Dashboard and click 'Settings' in the upper left beside the team dropdown
Select your Timezone and press 'Save'