Convert Date Time Zone To Another Time Zone In Apex

Sample Code:

//Get current date time in GMT format
Datetime dt = System.now();

//Convert it into Pacific Standard Time(PST).
String dtPST = dt.format('yyyy-MM-dd HH:mm:ss', 'PST');

System.debug('dt-' + dt);
System.debug('dtPST-' + dtPST);