You can have a different title when the tab is opened and closed using the title-opened and/or title-closed parameter.
Syntax
You can use the title-opened or title-closed parameter to override the default title in the tag. Or use both parameters. Doesn't really matter.
The 3 tabs in below example all have the same result. So choose whatever syntax method suits you best.
Indentation in example code is just for clarity. You should not indent your tags and text.
{tab title="This tab is now closed" title-opened="This tab is now opened"}
[TEXT]
{/tabs}
{tab title="This tab is now opened" title-closed="This tab is now closed"}
[TEXT]
{/tabs}
{tab title-opened=This tab is now opened" title-closed="This tab is now closed"}
[TEXT]
{/tabs}