(a) Whenever a sentence of a court-martial as lawfully adjudged and approved includes a forfeiture of pay or allowances in addition to confinement not suspended, the forfeiture shall apply to pay or allowances becoming due on or after the date the sentence is approved by the convening authority. No forfeiture shall extend to any pay or allowances accrued before that date.
(b) Any period of confinement included in a sentence of a court-martial shall begin to run from the date the sentence is adjudged by the court-martial, but periods during which the sentence to confinement is suspended or deferred shall be excluded in computing the service of the term of confinement.
(c) All sentences of courts-martial, except as provided for by subsections (a) and (b) of this Code section, shall be effective on the date ordered executed.