Notification delivered at an inappropriate time is usually considered an interruption. To ensure appropriate timing, we considered treating the self-initiated intermission as a period for interrupting users without causing distractions. This intermission is the time to report oneself as being available for an interaction or being ready for an interruption. This gives users the privilege of choosing a suitable time to handle interruptions without hampering any currently active task. Users' interruptibility is compared at the time of self-initiated intermission with two alternative types of interruption presentation: application switching and regular intervals. An empirical study showed that the self-initiated intermission is the best approach for interrupting users because their interruptibility is high at this time. We also found that users report on their intermission approximately up to four times during an hour long time span.