“Imprisonment” means incarceration in a correctional institution under a sentence of imprisonment and does not include “periodic imprisonment” under Article 7. “Imprisonment” also includes electronic monitoring or home detention served by an offender after (i) the offender has been committed to the custody of the sheriff to serve the sentence and (ii) the sheriff has placed the offender in an electronic monitoring or home detention program in accordance with Article 8A of Chapter V of this Code.