Hi, Dave. You posted in our Pre-Sales forum from a user account that doesn’t have any purchases associated with it.
We don’t answer support questions for The Events Calendar core/free or Event Tickets core/free or their paid add-ons in the Pre-Sales forum.
If you made your purchase(s) through a different user account, please login to that account and then post in one of the paid forums.
Thank you for your understanding and thank you for using our plugins.
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As a one-time courtesy, I will quickly answer your two questions
1)
You can reference this code snippet to customize the time interval:
https://gist.github.com/cliffordp/0e69539fc092d0c9e678
2)
It uses the Time settings from wp-admin > Settings > General (at /wp-admin/options-general.php) so please modify those settings.
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Other possibly helpful references: