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# CFGregorianUnitFlags

These option flags are used as a mask to indicate a specific set of fields in the CFGregorianDate or CFGregorianUnits structures.

```
struct CFGregorianUnitFlags
```

## Overview

These flags are used with functions such as [`CFGregorianDateIsValid(_:_:)`](/documentation/CoreFoundation/CFGregorianDateIsValid(_:_:)) and [`CFAbsoluteTimeGetDifferenceAsGregorianUnits(_:_:_:_:)`](/documentation/CoreFoundation/CFAbsoluteTimeGetDifferenceAsGregorianUnits(_:_:_:_:)) which operate on a CFGregorianDate or CFGregorianUnits structure. For more details, see the discussion of those functions.

## Topics

### Constants

[`kCFGregorianUnitsYears`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsYears)

Specifies the year field.

[`kCFGregorianUnitsMonths`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsMonths)

Specifies the month field.

[`kCFGregorianUnitsDays`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsDays)

Specifies the day field.

[`kCFGregorianUnitsHours`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsHours)

Specifies the hours field.

[`kCFGregorianUnitsMinutes`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsMinutes)

Specifies the minutes field.

[`kCFGregorianUnitsSeconds`](/documentation/CoreFoundation/CFGregorianUnitFlags/unitsSeconds)

Specifies the seconds field.

[`kCFGregorianAllUnits`](/documentation/CoreFoundation/CFGregorianUnitFlags/allUnits)

Specifies all fields.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`Sendable`](/documentation/Swift/Sendable)

[`ExpressibleByArrayLiteral`](/documentation/Swift/ExpressibleByArrayLiteral)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`SetAlgebra`](/documentation/Swift/SetAlgebra)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`OptionSet`](/documentation/Swift/OptionSet)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

---

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