Amazon Simple Workflow Service Timers

A timer enables you to notify your decider when a certain amount of time has elapsed. When responding to a decision task, the decider has the option to respond with a StartTimer decision. This decision specifies an amount of time after which the timer should fire. After the specified time has elapsed, Amazon SWF will add a TimerFired event to the workflow execution history and schedule a decision task. The decider can then use this information to inform further decisions. One common application for a timer is to delay the execution of an activity task. For example, a customer might want to take delayed delivery of an item.