Time zone settings in salesforce:
1.Go to Your name -> My Settings -> Personal -> Language & Time Zone.
2. Edit your time zone settings and select your local time zone.
3. Click Save.
4. Go to Administer -> Company profile -> Company information -> Select Edit button. 5. In the default time zone select your default time zone. 6. Save.
To change the time zone of the organization:
A. Classic UI
1. Navigate to Setup | Company Profile | Company information | Default Time Zone
2. Select the required time zone.
B. Lightning Experience UI
1. Click the Gear Icon | Setup | Company Settings | Company Information
2. Change the time zone.