What you need to consider is that both units do a specific function. The interval timer is energized for a specific length of time after supply voltage is applied to the timer. the supply voltage must be removed to reset the timer. While the recycle timer will apply the supply voltage once the off cycle begins timing. When the delay is finished, the timer will energize along with the on cycle. the timer will continue cycling until the supply voltage is removed, on and off can be equaled or of unequal duration. So to answer your question, no you cannot substitute one for the other.