How do I change the submission date & time to sydney australia time zone

Greetings and thank you for your message.

You need to update the timezone from your settings. 

To do this, please click on your profile image from the upper right corner, and select the settings link. Once you do, you will be able to update your timezone:

After you update it here, you will see the updated time in your submissions.

For additional information, please refer to the following article:
https://www.jotform.com/help/346-How-to-Change-Submission-Date-to-a-Different-Format-and-Timezone

Please let us know if this resolved your problem.