When notified that its timer has expired, a DelayActivity completes its execution.
You can set a time out on the DelayActivity so that your workflow pauses before resuming execution. You specify the TimeoutDuration using TimeSpan. This causes your workflow to pause until the specified TimeSpan has elapsed.
The DelayActivity is guaranteed to complete no sooner than the indicated TimeoutDuration. The delay can take longer because the timer notification might occur some time after the TimeoutDuration is reached. One reason for a longer delay is if the workflow is running under high system stress in a server environment.