| at fixed intervals(expression, time, period, iteration) |
| at various times(expression, time, period, iteration) |
| at varying times(expression, time, period, iteration) |
| daily(adjective, adverb, time, period, iteration) |
| hourly(adjective, adverb, time, period, iteration) |
| monthly(adjective, adverb, time, period, iteration) |
| weekly(adjective, adverb, time, period, iteration) |
| yearly(adjective, adverb, time, period, iteration) |
| every once in a while(expression, time, period, iteration) |
| every so often(expression, time, period, iteration) |
| on certain occasions(expression, time, period, iteration) |
| on separate occasions(expression, time, period, iteration) |
| alternate(adjective, time, period, iteration) |
| annual(adjective, time, period, iteration) |
| broken(adjective, time, period, iteration) |
| centennial(adjective, time, period, iteration) |
| continuing(adjective, time, period, iteration) |
| cyclic(adjective, time, period, iteration) |
| cyclical(adjective, time, period, iteration) |
| episodic(adjective, time, period, iteration) |