## When to Use<a name="section18502174174019"></a>
## When to Use
You can set your application to call the **ReminderRequest** class to create scheduled reminders for countdown timers, calendar events, and alarm clocks. When the created reminders are published, the timing and pop-up notification functions of your application will be taken over by the reminder agent in the background, even when your application is frozen or exits.
You can set your application to call the **ReminderRequest** class to create scheduled reminders for countdown timers, calendar events, and alarm clocks. When the created reminders are published, the timing and pop-up notification functions of your application will be taken over by the reminder agent in the background, even when your application is frozen or exits.
## Available APIs<a name="section1633115419401"></a>
## Available APIs
**reminderAgent** encapsulates the methods for publishing and canceling reminders.
**reminderAgent** encapsulates the methods for publishing and canceling reminders.
| function publishReminder(reminderReq: ReminderRequest, callback: AsyncCallback\<number>): void;<br>function publishReminder(reminderReq: ReminderRequest): Promise\<number>; | Publishes a scheduled reminder.<br>The maximum number of valid notifications (excluding expired ones that will not pop up again) is 30 for one application and 2000 for the entire system. |
</tr>
| function cancelReminder(reminderId: number, callback: AsyncCallback\<void>): void;<br/>function cancelReminder(reminderId: number): Promise\<void>; | Cancels a specified reminder. (The value of **reminderId** is obtained from the return value of **publishReminder**.) |
</thead>
| function getValidReminders(callback: AsyncCallback<Array\<ReminderRequest>>): void;<br/>function getValidReminders(): Promise<Array\<ReminderRequest>>; | Obtains all valid reminders set by the current application. |
| function cancelAllReminders(callback: AsyncCallback\<void>): void;<br/>function cancelAllReminders(): Promise\<void>; | Cancels all reminders set by the current application. |
| function addNotificationSlot(slot: NotificationSlot, callback: AsyncCallback\<void>): void;<br/>function addNotificationSlot(slot: NotificationSlot): Promise<void>; | Registers a NotificationSlot instance to be used by the reminder. |
</td>
| function removeNotificationSlot(slotType: notification.SlotType, callback: AsyncCallback\<void>): void;function removeNotificationSlot(slotType: notification.SlotType): Promise\<void>; | Removes a NotificationSlot instance of a specified type. |
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p13562171015712"><aname="p13562171015712"></a><aname="p13562171015712"></a>Publishes a scheduled reminder.</p>
<pid="p9591131611311"><aname="p9591131611311"></a><aname="p9591131611311"></a>The maximum number of valid notifications (excluding expired ones that will not pop up again) is 30 for one application and 2000 for the entire system.</p>
**ActionButtonType** enumerates types of buttons displayed in a reminder notification.
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p3465939173317"><aname="p3465939173317"></a><aname="p3465939173317"></a>Cancels a specified reminder. (The value of <strongid="b83631346162614"><aname="b83631346162614"></a><aname="b83631346162614"></a>reminderId</strong> is obtained from the return value of <strongid="b236420465267"><aname="b236420465267"></a><aname="b236420465267"></a>publishReminder</strong>.)</p>
| ACTION_BUTTON_TYPE_CLOSE | Close button, which can be tapped to stop the reminder alert tone, close the reminder notification, and cancel the reminder snoozing. |
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p184651639143320"><aname="p184651639143320"></a><aname="p184651639143320"></a>Obtains all valid reminders set by the current application.</p>
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p19451839143310"><aname="p19451839143310"></a><aname="p19451839143310"></a>Cancels all reminders set by the current application.</p>
**ActionButton** defines a button displayed in the reminder notification.
</td>
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p142081320344"><aname="p142081320344"></a><aname="p142081320344"></a>Registers a <ahref="../nottoctopics/en-us_topic_0000001180018813.md#section1382174172015">NotificationSlot</a> instance to be used by the reminder.</p>
<tdclass="cellrowborder"valign="top"width="42.61%"headers="mcps1.2.3.1.2 "><pid="p1407141783410"><aname="p1407141783410"></a><aname="p1407141783410"></a>Removes a <ahref="../nottoctopics/en-us_topic_0000001180018813.md#section1382174172015">NotificationSlot</a> instance of a specified type.</p>
| title | string | Yes | Text on the button. |
</td>
| type | ActionButtonType | Yes | Button type. |
</tr>
</tbody>
**WantAgent** sets the package and ability that are redirected to when the reminder notification is clicked.
</table>
**Table 5** WantAgent instance
**ActionButtonType** enumerates types of buttons displayed in a reminder notification.
**MaxScreenWantAgent** sets the name of the target package and ability to start automatically when the reminder arrives and the device is not in use. If the device is in use, a notification will be displayed.
<tdclass="cellrowborder"valign="top"width="61.809999999999995%"headers="mcps1.2.3.1.2 "><pid="p13547161217154"><aname="p13547161217154"></a><aname="p13547161217154"></a>Close button, which can be tapped to stop the reminder alert tone, close the reminder notification, and cancel the reminder snoozing.</p>
| maxScreenWantAgent | MaxScreenWantAgent | No | Information about the ability that is automatically started when the reminder arrives. If the device is in use, a notification will be displayed. |
| snoozeContent | string | No | Extended content to be displayed when the reminder is snoozing. |
</td>
| notificationId | number | No | Notification ID used by the reminder. For details, see the API reference of the **NotificationRequest.setNotificationId(int id)** method. |
</tr>
| slotType | SlotType | No | Type of the slot used by the reminder. |
<tdclass="cellrowborder"valign="top"width="52.04%"headers="mcps1.2.5.1.4 "><pid="p16804121112213"><aname="p16804121112213"></a><aname="p16804121112213"></a>Text on the button.</p>
<tdclass="cellrowborder"valign="top"width="51.66483351664834%"headers="mcps1.2.5.1.4 "><pid="p24967514355"><aname="p24967514355"></a><aname="p24967514355"></a>Name of the package redirected to when the reminder notification is clicked.</p>
<tdclass="cellrowborder"valign="top"width="51.66483351664834%"headers="mcps1.2.5.1.4 "><pid="p14966511359"><aname="p14966511359"></a><aname="p14966511359"></a>Name of the ability redirected to when the reminder notification is clicked.</p>
</td>
</tr>
</tbody>
</table>
**MaxScreenWantAgent** sets the name of the target package and ability to start automatically when the reminder arrives and the device is not in use. If the device is in use, a notification will be displayed.
<tdclass="cellrowborder"valign="top"width="51.300000000000004%"headers="mcps1.2.5.1.4 "><pid="p13390173423710"><aname="p13390173423710"></a><aname="p13390173423710"></a>Name of the package that is automatically started when the reminder arrives and the device is not in use.</p>
<tdclass="cellrowborder"valign="top"width="51.300000000000004%"headers="mcps1.2.5.1.4 "><pid="p639093443717"><aname="p639093443717"></a><aname="p639093443717"></a>Name of the ability that is automatically started when the reminder arrives and the device is not in use.</p>
</td>
</tr>
</tbody>
</table>
**ReminderRequest** defines the reminder to publish.
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p1019193963812"><aname="p1019193963812"></a><aname="p1019193963812"></a>Type of the reminder.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p3191133963820"><aname="p3191133963820"></a><aname="p3191133963820"></a>Action button displayed in the reminder notification.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p819218395387"><aname="p819218395387"></a><aname="p819218395387"></a>Information about the ability that is redirected to when the notification is clicked.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p119213933815"><aname="p119213933815"></a><aname="p119213933815"></a>Information about the ability that is automatically started when the reminder arrives. If the device is in use, a notification will be displayed.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p2286115418440"><aname="p2286115418440"></a><aname="p2286115418440"></a>Extended content to be displayed when the reminder expires.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p66021050104419"><aname="p66021050104419"></a><aname="p66021050104419"></a>Extended content to be displayed when the reminder is snoozing.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p16327733456"><aname="p16327733456"></a><aname="p16327733456"></a>Notification ID used by the reminder. For details, see the API reference of the <strongid="b1391142771410"><aname="b1391142771410"></a><aname="b1391142771410"></a>NotificationRequest::SetNotificationId(int32_t id)</strong> method.</p>
<tdclass="cellrowborder"valign="top"width="50.480000000000004%"headers="mcps1.2.5.1.4 "><pid="p193705238459"><aname="p193705238459"></a><aname="p193705238459"></a>Type of the slot used by the reminder.</p>
</td>
</tr>
</tbody>
</table>
**ReminderRequestCalendar** extends **ReminderRequest** and defines a reminder for a calendar event.
For the application to run properly, if both **repeatMonths** and **repeatDays** are not specified, the earliest reminder time must be later than the current time.
For the application to run properly, if both **repeatMonths** and **repeatDays** are not specified, the earliest reminder time must be later than the current time.
<tdclass="cellrowborder"valign="top"width="50.3%"headers="mcps1.2.5.1.4 "><pid="p1031461511522"><aname="p1031461511522"></a><aname="p1031461511522"></a>Reminder time, accurate to the minute.</p>
<tdclass="cellrowborder"valign="top"width="50.3%"headers="mcps1.2.5.1.4 "><pid="p2031411555218"><aname="p2031411555218"></a><aname="p2031411555218"></a>Months in which the reminder repeats. The value range is 1 to 12.</p>
<tdclass="cellrowborder"valign="top"width="50.3%"headers="mcps1.2.5.1.4 "><pid="p18314141515212"><aname="p18314141515212"></a><aname="p18314141515212"></a>Date on which the reminder repeats. The value range is 1 to 31.</p>
</td>
</tr>
</tbody>
</table>
**ReminderRequestAlarm** extends **ReminderRequest** and defines a reminder for the alarm clock.
<tdclass="cellrowborder"valign="top"width="49.86%"headers="mcps1.2.5.1.4 "><pid="p1770161618444"><aname="p1770161618444"></a><aname="p1770161618444"></a>Hour portion of the reminder time. The value range is 0 to 23.</p>
<tdclass="cellrowborder"valign="top"width="49.86%"headers="mcps1.2.5.1.4 "><pid="p17703161445"><aname="p17703161445"></a><aname="p17703161445"></a>Minute portion of the reminder time. The value range is 0 to 59.</p>
<tdclass="cellrowborder"valign="top"width="49.86%"headers="mcps1.2.5.1.4 "><pid="p16101423134917"><aname="p16101423134917"></a><aname="p16101423134917"></a>Days of a week when the reminder repeats. The value range is 1 to 7.</p>
</td>
</tr>
</tbody>
</table>
**ReminderRequestTimer** extends **ReminderRequest** and defines a reminder for a scheduled timer.
<tdclass="cellrowborder"valign="top"width="49.17%"headers="mcps1.2.5.1.4 "><pid="p7214112014509"><aname="p7214112014509"></a><aname="p7214112014509"></a>Number of seconds in the countdown timer.</p>
</td>
</tr>
</tbody>
</table>
**LocalDateTime** defines a **LocalDateTime** instance.
> **NOTE:** The initial APIs of this module are supported since API version 4. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>The initial APIs of this module are supported since API version 4. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Module to Import<a name="section7480141454919"></a>
| delay | number | No | Number of milliseconds delayed before the execution. If this parameter is left empty, the default value **0** is used, which means that the execution starts immediately or as soon as possible. |
</th>
| ...args | Array\<any> | No | Additional parameter to pass to the handler after the timer goes off. |
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p788516491307"><a name="p788516491307"></a><a name="p788516491307"></a>Function to be called after the timer goes off.</p>
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p1943234615"><a name="p1943234615"></a><a name="p1943234615"></a>Number of milliseconds delayed before the execution. If this parameter is left empty, the default value <strong id="b1264512254010"><a name="b1264512254010"></a><a name="b1264512254010"></a>0</strong> is used, which means that the execution starts immediately or as soon as possible.</p>
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p139991022863"><a name="p139991022863"></a><a name="p139991022863"></a>Additional parameter to pass to the handler after the timer goes off.</p>
<td class="cellrowborder" valign="top" width="69.94%" headers="mcps1.1.5.1.4 "><p id="p6426183941319"><a name="p6426183941319"></a><a name="p6426183941319"></a>ID of the timer to cancel, which is returned by <strong id="b5804644564"><a name="b5804644564"></a><a name="b5804644564"></a>setTimeout()</strong></p>
</td>
</tr>
</tbody>
</table>
- Example
```
export default {
clearTimeOut() {
var timeoutID = setTimeout(function() {
console.log('do after 1s delay.');
}, 1000);
clearTimeout(timeoutID);
}
}
}
```
}
```
## clearTimeout
## setInterval<a name="section3644185910144"></a>
clearTimeout(timeoutID: number): void
setInterval\(handler\[, delay\[, ...args\]\]\): number
Cancels the timer created via **setTimeout()**.
Sets a repeating timer for the system to repeatedly call a function at a fixed interval.
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p4645155931418"><a name="p4645155931418"></a><a name="p4645155931418"></a>Function to be called repeatedly</p>
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p13645559141415"><a name="p13645559141415"></a><a name="p13645559141415"></a>Number of milliseconds delayed before the execution</p>
<td class="cellrowborder" valign="top" width="62.91%" headers="mcps1.1.5.1.4 "><p id="p12645105991413"><a name="p12645105991413"></a><a name="p12645105991413"></a>Additional parameter to pass to the handler after the timer goes off</p>
<td class="cellrowborder" valign="top" width="69.94%" headers="mcps1.1.5.1.4 "><p id="p7646459141416"><a name="p7646459141416"></a><a name="p7646459141416"></a>ID of the repeating timer to cancel, which is returned by <strong id="b1855918269134"><a name="b1855918269134"></a><a name="b1855918269134"></a>setInterval()</strong>.</p>
</td>
```
</tr>
export default {
</tbody>
setInterval() {
</table>
var intervalID = setInterval(function() {
console.log('do very 1s.');
- Example
}, 1000);
```
export default {
clearInterval() {
var intervalID = setInterval(function() {
console.log('do very 1s.');
}, 1000);
clearInterval(intervalID);
}
}
}
```
}
```
## clearInterval
clearInterval(intervalID: number): void
Cancels the repeating timer set via **setInterval()**.
