It's best to alert the brand you collaborate with about this immediately so they can try to accommodate. Our agreements (once mutually agreed) are binding and include post dates. It’s important to keep in mind that the brands specify post times that align with their marketing initiatives and campaigns, so in some cases they cannot accommodate.
That said, they’re people too and we understand circumstances change and unexpected things happen.
If you have any questions about the post date(s), please reach out to the brand within Content Studio of the campaign.