Tired of manually configuring the the time zone for a new site collection?
You can change the default in the SharePoint Admin Centre.
It doesn’t fix the date format on the site however, you still need to do that in the site collection Regional Settings.
We only use the date format YYYY-MM-DD so we can sort content in either ascending or descending order, so we change our Locale to South Africa to get that.
If you think this should be something we can set ourselves globally too, please vote it up on UserVoice.