Mr. Chair, section 217 merely refers to the ability for review and remission, so if there's an order for remission, that would affect the running of the time.
Subsection (3) refers to the special case where a sentence cannot be lawfully carried out by reason of a vessel being at sea. That would be one exceptional case that would depart from the general rule.
Otherwise, these are just minor adjustments that are being accomplished in that section.