For shared hosting customers, you cannot modify the servers global timezone value but you can modify the timezone for PHP through your cPanel following the steps below.
Step 1: Login to cPanel and click the Select PHP Version icon founder under the Software section.
Step 2: Click the Options tab at the top of the screen to modify PHP options
Step 3: Click the value next to date.timezone to edit the timezone setting.
Your changes will be saved automatically
An example value you could put in the field would be: America/New_York
Note:
A list of available PHP timezones can be found here.