> ## Documentation Index > Fetch the complete documentation index at: https://chronotab.app/llms.txt > Use this file to discover all available pages before exploring further. # Background ## Functions ### getNextOccurrenceFrom(timeStr, fromTimestamp) ⇒ `number` | `null` Calculates the next occurrence of a given time string strictly after a specified timestamp. Handles time strings in "HH:MM" format or ISO strings by extracting "HH:MM". If the calculated time on the same day as fromTimestamp is in the past or same as fromTimestamp, it advances to the next day. ### getNextWeeklyOccurrenceFrom(timeStr, daysOfWeek, fromTimestamp) ⇒ `number` | `null` Calculates the next weekly occurrence of a given time on specified days of the week, strictly after a specified timestamp. Handles time strings in "HH:MM" format or ISO strings by extracting "HH:MM". It finds the earliest possible time across all specified daysOfWeek that is after fromTimestamp. ### pruneClearedMissedAlarms(clearedList) ⇒ `Array.` Utility to prune cleared missed alarms older than a defined period (currently 30 days). Filters an array of cleared missed alarm objects, removing entries whose `clearedAt` timestamp is older than the pruning threshold relative to the current time. ### checkMissedAlarmsOnStartup() Checks for schedules that should have run while the extension was inactive (e.g., browser closed). If missed alarms are enabled and found, it stores them in `chrome.storage.local` and displays a notification to the user. For recurring schedules, it identifies the latest missed instance. ### createContextMenus() Creates and configures context menus for the extension. It sets up the following: * A parent menu "Add current page to Chronotab" (context: `page`) with options to: "Create New Schedule..." * Add to existing schedules (if any are present). * A parent menu "Run Chronotab schedule now" (contexts: `action`, `browser_action`, `page`) with options to: Run existing schedules (if any are present). * Shows "No schedules configured" (disabled) if none exist. This function first removes all existing context menus to ensure a clean setup before recreating them. Schedule data is fetched from `chrome.storage.sync` to populate the menu items. ## Typedefs ### Alarm : `object` Represents a Chrome alarm object used by the extension. ### MessageRequest : `object` Defines the structure of messages sent to the background script for various actions. ### SendResponse : `function` A callback function used to send a response to a message sender in Chrome extensions. ### ContextMenuOnClickData : `object` Provides information about the context menu item that was clicked. ### Tab : `object` Represents a browser tab in Chrome. ### OnInstalledDetails : `object` Contains details about the installation or update event of the extension. ### StorageChange : `object` Describes the change in a single storage item, as provided by `chrome.storage.onChanged`. ### StorageChanges : `object.` An object where each key is the name of a storage item that changed, and the value is a StorageChange object. ## getNextOccurrenceFrom(timeStr, fromTimestamp) ⇒ `number` | `null` Calculates the next occurrence of a given time string strictly after a specified timestamp. Handles time strings in "HH:MM" format or ISO strings by extracting "HH:MM". If the calculated time on the same day as fromTimestamp is in the past or same as fromTimestamp, it advances to the next day. **Kind**: global function\ **Returns**: `number` | `null` - The timestamp of the next occurrence, or null if the time string is invalid or calculation fails. | Param | Type | Description | | ------------- | -------- | ------------------------------------------------------------------------------------- | | timeStr | `string` | The time string, e.g., "14:30" or an ISO string like "2023-01-01T14:30:00". | | fromTimestamp | `number` | The timestamp (milliseconds since epoch) from which to calculate the next occurrence. | ## getNextWeeklyOccurrenceFrom(timeStr, daysOfWeek, fromTimestamp) ⇒ `number` | `null` Calculates the next weekly occurrence of a given time on specified days of the week, strictly after a specified timestamp. Handles time strings in "HH:MM" format or ISO strings by extracting "HH:MM". It finds the earliest possible time across all specified daysOfWeek that is after fromTimestamp. **Kind**: global function\ **Returns**: `number` | `null` - The timestamp of the earliest next weekly occurrence, or null if inputs are invalid or no valid occurrence is found. | Param | Type | Description | | ------------- | ---------------- | ------------------------------------------------------------------------------------- | | timeStr | `string` | The time string, e.g., "14:30" or an ISO string. | | daysOfWeek | `Array.` | An array of day numbers (0 for Sunday, 1 for Monday, ..., 6 for Saturday). | | fromTimestamp | `number` | The timestamp (milliseconds since epoch) from which to calculate the next occurrence. | ## pruneClearedMissedAlarms(clearedList) ⇒ `Array.` Utility to prune cleared missed alarms older than a defined period (currently 30 days). Filters an array of cleared missed alarm objects, removing entries whose `clearedAt` timestamp is older than the pruning threshold relative to the current time. **Kind**: global function\ **Returns**: `Array.` - A new array containing only the cleared missed alarm entries that are within the 30-day retention period. | Param | Type | Description | | ----------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | clearedList | `Array.` | Array of cleared missed alarm objects. Each object is expected to have a `clearedAt` property (timestamp in milliseconds). | ## checkMissedAlarmsOnStartup() Checks for schedules that should have run while the extension was inactive (e.g., browser closed). If missed alarms are enabled and found, it stores them in `chrome.storage.local` and displays a notification to the user. For recurring schedules, it identifies the latest missed instance. **Kind**: global function ## createContextMenus() Creates and configures context menus for the extension. It sets up the following: * A parent menu "Add current page to Chronotab" (context: `page`) with options to: * "Create New Schedule..." * Add to existing schedules (if any are present). * A parent menu "Run Chronotab schedule now" (contexts: `action`, `browser_action`, `page`) with options to: * Run existing schedules (if any are present). * Shows "No schedules configured" (disabled) if none exist. This function first removes all existing context menus to ensure a clean setup before recreating them. Schedule data is fetched from `chrome.storage.sync` to populate the menu items. **Kind**: global function ## Alarm : `object` Represents a Chrome alarm object used by the extension. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ---- | -------- | ------------------------------------------------------------- | | name | `string` | The name of the alarm, typically prefixed with a schedule ID. | ## MessageRequest : `object` Defines the structure of messages sent to the background script for various actions. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ---------------- | -------- | -------------------------------------------------------------------------------- | | action | `string` | The type of action to perform (e.g., "runMissedAlarm", "clearMissedAlarmEntry"). | | \[scheduleId] | `string` | The ID of the schedule, relevant for schedule-specific actions. | | \[missedRunTime] | `number` | The specific timestamp of a missed run, used for clearing specific entries. | ## SendResponse : `function` A callback function used to send a response to a message sender in Chrome extensions. **Kind**: global typedef | Param | Type | Description | | ----------- | ----- | ---------------------------------- | | \[response] | `any` | The data to be sent as a response. | ## ContextMenuOnClickData : `object` Provides information about the context menu item that was clicked. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ---------- | -------- | ------------------------------------------------------------------ | | menuItemId | `\*` | The ID of the menu item that was clicked. | | \[pageUrl] | `string` | The URL of the page where the context menu was clicked. | | \[linkUrl] | `string` | If the clicked item was a link, this is the URL of the link. | | \[srcUrl] | `string` | If the clicked item was an image or video, this is its source URL. | ## Tab : `object` Represents a browser tab in Chrome. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ------ | -------- | ---------------------------------- | | \[id] | `number` | The unique identifier for the tab. | | \[url] | `string` | The URL the tab is displaying. | ## OnInstalledDetails : `object` Contains details about the installation or update event of the extension. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ------------------ | -------- | ----------------------------------------------------------------------- | | reason | `string` | The reason for the event (e.g., "install", "update", "chrome\_update"). | | \[previousVersion] | `string` | The previous version of the extension, if it was updated. | ## StorageChange : `object` Describes the change in a single storage item, as provided by `chrome.storage.onChanged`. **Kind**: global typedef\ **Properties** | Name | Type | Description | | ----------- | ---- | ------------------------------------------------------------ | | \[oldValue] | `\*` | The old value of the item, if it existed before this change. | | \[newValue] | `\*` | The new value of the item, if it was set or changed. | ## StorageChanges : `object.` An object where each key is the name of a storage item that changed, and the value is a StorageChange object. **Kind**: global typedef