periodic
pe-ri-od-ic
adjective
Occurring or appearing at regular, fixed intervals of time.
"The engine needs periodic checks."
Thesaurus
Synonyms: biennial, periodical, triennial, yearly, half-yearly, hebdomadary, bimestrial, cyclic, semimonthly, half-hourly, biyearly, midweekly
Antonyms: aperiodic, nonperiodic