wp-includes/customize/class-wp-customize-date-time-control.php:73Don't render the control's content - it's rendered with a JS template.
public function render_content() {}Introduced in 4.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/customize/class-wp-customize-date-time-control.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.