# Class CalendarExtensions

OptimaJet.Workflow.Core.Runtime.Calendars.CalendarExtensions

Provides extension methods for configuring [Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) instances and calculating intervals using workflow calendar rules.

Namespace: [OptimaJet.Workflow.Core.Runtime.Calendars](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/)

```csharp
public static class CalendarExtensions
```

## Methods

`public static TimeSpan GetInterval(this ICalendar calendar, string value, DateTime startDateTime)` 

Gets the interval represented by `value`, optionally applying calendar-specific working-day rules.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `calendar` | `ICalendar` | Calendar settings used for working-time values. |
| `value` | `String` | A timer expression string. |
| `startDateTime` | `DateTime` | The start point for the interval calculation. |

### Returns

| Type | Description |
| --- | --- |
| `TimeSpan` | A [TimeSpan](https://learn.microsoft.com/dotnet/api/system.timespan) value that can be added to `startDateTime` to get the target time. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentNullException` | Thrown when `value` is [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null). |
| `ArgumentException` | Thrown when `value` mixes calendar and non-calendar interval units. |

### Remarks

If `value` contains calendar-prefixed units (`wyear`, `wmonth`, `wdays`, `whours`, `wminutes`), calendar working-day logic is used. Otherwise normal interval parsing is delegated to [HelperDateTime.GetInterval(string)](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Helpers/HelperDateTime/).

`public static Calendar SetWorkingHours(this Calendar calendar, TimeSpan workingHours)` 

Sets the total working hours per workday and returns the same [Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) instance.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `calendar` | `Calendar` | Calendar instance to update. |
| `workingHours` | `TimeSpan` | Working hours to configure. |

### Returns

| Type | Description |
| --- | --- |
| `Calendar` | The updated `calendar`. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentOutOfRangeException` | Thrown if `workingHours` is greater than 24 hours, or if it causes the workday to exceed 24 hours when combined with [Calendar.StartOfWork](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/). |

### Remarks

The value is normalized using [HelperDateTime.Floor(TimeSpan)](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Helpers/HelperDateTime/), so seconds and milliseconds are dropped.

`public static Calendar SetStartOfWork(this Calendar calendar, TimeSpan startTimeOfDay)` 

Sets the start time of the workday and returns the same [Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) instance.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `calendar` | `Calendar` | Calendar instance to update. |
| `startTimeOfDay` | `TimeSpan` | Time of day when the working period starts. |

### Returns

| Type | Description |
| --- | --- |
| `Calendar` | The updated `calendar`. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentOutOfRangeException` | Thrown if `startTimeOfDay` is greater than 24 hours, or if it causes the workday to exceed 24 hours with [Calendar.WorkingHours](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/). |

### Remarks

The value is normalized using [HelperDateTime.Floor(TimeSpan)](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Helpers/HelperDateTime/), so seconds and milliseconds are dropped.

`public static Calendar SetWeekends(this Calendar calendar, params DayOfWeek[] weekends)` 

Adds the specified weekend days to [Calendar.Weekends](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) and returns the same [Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) instance.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `calendar` | `Calendar` | Calendar instance to update. |
| `weekends` | `DayOfWeek[]` | Weekday values to add as weekends. |

### Returns

| Type | Description |
| --- | --- |
| `Calendar` | The updated `calendar`. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentNullException` | Thrown when `weekends` is [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null). |

`public static Calendar SetYears(this Calendar calendar, params Year[] years)` 

Adds year-level settings to the calendar and returns the same [Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) instance.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `calendar` | `Calendar` | Calendar instance to update. |
| `years` | `Year[]` | [Year](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Year/) objects to register by year number. |

### Returns

| Type | Description |
| --- | --- |
| `Calendar` | The updated `calendar`. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentException` | Thrown if a value with the same [Year.YearNumber](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Year/) already exists in [Calendar.Years](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/). |

[Previous Calendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/Calendar/) [Next ICalendar](https://api.workflowengine.io/core/OptimaJet.Workflow.Core.Runtime.Calendars/ICalendar/)