Time as essence: failure to perform on time makes the contract voidable unless acceptance is accompanied by notice to claim compensation. If the parties intended that time be of the essence, failure to perform at or before the specified time renders the unperformed portion of the contract voidable at the promisee's option. If time was not of the essence, the contract is not voidable for late performance; instead the promisee may claim compensation for loss caused by the delay. Acceptance of late performance bars compensation claims unless the promisee gives notice of intent to claim compensation at the time of acceptance.