Same word as round-the-clock:

aeonian, around-the-clock, ceaseless, connected, consecutive, constant, continuous, dateless, endless, enduring, eternal, everlasting, frequent, incessant, interminable, nonstop, oft-repeated, ongoing, permanent, perpetual, persistent, persisting, recurrent, regular, relentless, repeated, repetitive, running, staying, steady, timeless, unbroken, unceasing, unchanging, unending, unfailing, unflagging, uninterrupted, unremitting, unvarying, unwaning