Moment
Moment, point in time, hour, second, juncture, phase, point, occasion, minute, instant, stage, and o'clock.
While
While, stretch, span, interval, period of time, duration, space, stage, patch, spell, stint, season, period, length of time, run, phase, and term.
Era
Era, epoch, aeon, days, date, age, period, years, and generation.
Lifetime
Lifetime, life span, days, existence, this mortal coil, life, allotted span, time on earth, threescore years and ten, and born days.
Heyday
Heyday, hour, best days/years, vigour, salad days, day, prime, youth, springtime, and maturity.
Rhythm
Rhythm, beat, flow, measure, pattern, stress, tempo, pulse, metre, cadence, and accent.
Schedule
Schedule, set up, organize, fix up, book, slot in, timetable, programme, slate, set, arrange, fix, fix a time for, line up, prearrange, bill, and plan.