Struct YearMonth

A year and month in a particular calendar. This is effectively LocalDate without the day-of-month component.
Since 3.0.x
Availability netstandard2.0
Implements
IEquatable<YearMonth>
IComparable<YearMonth>
IComparable
IFormattable
IXmlSerializable
Inherited Members
ValueType.ToString()
Object.Equals(Object, Object)
Object.GetType()
Object.ReferenceEquals(Object, Object)
Namespace: NodaTime
Assembly: NodaTime.dll
Syntax
[TypeConverter(typeof(YearMonthTypeConverter))]
public struct YearMonth : IEquatable<YearMonth>, IComparable<YearMonth>, IComparable, IFormattable, IXmlSerializable
Remarks

Values can freely be compared for equality: a value in a different calendar system is not equal to a value in a different calendar system. However, ordering comparisons fail with System.ArgumentException; attempting to compare values in different calendars almost always indicates a bug in the calling code.

Constructors

YearMonth(Era, Int32, Int32)

Constructs an instance for the given era, year of era and month in the ISO calendar.
Since 3.0.x
Availability netstandard2.0
Declaration
public YearMonth(Era era, int yearOfEra, int month)
Parameters
Type Name Description
Era era The era within which to create a year/month. Must be a valid era within the ISO calendar.
Int32 yearOfEra The year of era.
Int32 month The month of year.
Sample snippet
using NodaTime;
using NodaTime.Calendars;
using System;

YearMonth yearMonth = new YearMonth(Era.Common, 1994, 5);
Console.WriteLine(yearMonth.Year);
Console.WriteLine(yearMonth.Month);
Console.WriteLine(yearMonth.Calendar);
Console.WriteLine(yearMonth.Era);

Output:

1994
5
ISO
CE
Exceptions
Type Condition
ArgumentOutOfRangeException The parameters do not form a valid year/month.

YearMonth(Era, Int32, Int32, CalendarSystem)

Constructs an instance for the given era, year of era and month in the specified calendar.
Since 3.0.x
Availability netstandard2.0
Declaration
public YearMonth(Era era, int yearOfEra, int month, CalendarSystem calendar)
Parameters
Type Name Description
Era era The era within which to create a year/month. Must be a valid era within the specified calendar.
Int32 yearOfEra The year of era.
Int32 month The month of year.
CalendarSystem calendar Calendar system in which to create the year/month.
Sample snippet
using NodaTime;
using NodaTime.Calendars;
using System;

YearMonth yearMonth = new YearMonth(Era.Common, 2019, 5, CalendarSystem.Gregorian);
Console.WriteLine(yearMonth.Year);
Console.WriteLine(yearMonth.Month);
Console.WriteLine(yearMonth.Calendar);
Console.WriteLine(yearMonth.Era);

Output:

2019
5
Gregorian
CE
Exceptions
Type Condition
ArgumentOutOfRangeException The parameters do not form a valid year/month.

YearMonth(Int32, Int32)

Constructs an instance for the given year and month in the ISO calendar.
Since 3.0.x
Availability netstandard2.0
Declaration
public YearMonth(int year, int month)
Parameters
Type Name Description
Int32 year The year. This is the "absolute year", so a value of 0 means 1 BC, for example.
Int32 month The month of year.
Sample snippet
using NodaTime;
using System;

YearMonth yearMonth = new YearMonth(2019, 5);
Console.WriteLine(yearMonth.Year);
Console.WriteLine(yearMonth.Month);
Console.WriteLine(yearMonth.Calendar);

Output:

2019
5
ISO
Exceptions
Type Condition
ArgumentOutOfRangeException The parameters do not form a valid year/month.

YearMonth(Int32, Int32, CalendarSystem)

Constructs an instance for the given year, month and day in the specified calendar.
Since 3.0.x
Availability netstandard2.0
Declaration
public YearMonth(int year, int month, CalendarSystem calendar)
Parameters
Type Name Description
Int32 year The year. This is the "absolute year", so, for the ISO calendar, a value of 0 means 1 BC, for example.
Int32 month The month of year.
CalendarSystem calendar Calendar system in which to create the year/month.
Sample snippet
using NodaTime;
using System;

YearMonth yearMonth = new YearMonth(2014, 3, CalendarSystem.Julian);
Console.WriteLine(yearMonth.Year);
Console.WriteLine(yearMonth.Month);
Console.WriteLine(yearMonth.Calendar);

Output:

2014
3
Julian
Exceptions
Type Condition
ArgumentOutOfRangeException The parameters do not form a valid year/month.

Properties

Calendar

Gets the calendar system associated with this year/month.
Since 3.0.x
Availability netstandard2.0
Declaration
public CalendarSystem Calendar { get; }
Property Value
Type Description
CalendarSystem The calendar system associated with this year/month.

Era

Gets the era of this year/month.
Since 3.0.x
Availability netstandard2.0
Declaration
public Era Era { get; }
Property Value
Type Description
Era The era of this year/month.

Month

Gets the month of this year/month within the year.
Since 3.0.x
Availability netstandard2.0
Declaration
public int Month { get; }
Property Value
Type Description
Int32 The month of this year/month within the year.

Year

Gets the year of this year/month.
Since 3.0.x
Availability netstandard2.0
Declaration
public int Year { get; }
Property Value
Type Description
Int32 The year of this year/month.
Remarks
This returns the "absolute year", so, for the ISO calendar, a value of 0 means 1 BC, for example.

YearOfEra

Gets the year of this value within the era.
Since 3.0.x
Availability netstandard2.0
Declaration
public int YearOfEra { get; }
Property Value
Type Description
Int32 The year of this value within the era.

Methods

AddSchema(XmlSchemaSet)

Adds the XML schema type describing the structure of the YearMonth XML serialization to the given xmlSchemaSet.
Since 3.0.x
Availability netstandard2.0
Declaration
public static XmlQualifiedName AddSchema(XmlSchemaSet xmlSchemaSet)
Parameters
Type Name Description
XmlSchemaSet xmlSchemaSet The XML schema set provided by System.Xml.Serialization.XmlSchemaExporter.
Returns
Type Description
XmlQualifiedName The qualified name of the schema type that was added to the xmlSchemaSet.

CompareTo(YearMonth)

Indicates whether this year/month is earlier, later or the same as another one. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public int CompareTo(YearMonth other)
Parameters
Type Name Description
YearMonth other The other year/month to compare this one with
Returns
Type Description
Int32 A value less than zero if this year/month is earlier than other; zero if this year/month is the same as other; a value greater than zero if this date is later than other.
Exceptions
Type Condition
ArgumentException The calendar system of other is not the same as the calendar system of this value.

Equals(YearMonth)

Compares two YearMonth values for equality. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public bool Equals(YearMonth other)
Parameters
Type Name Description
YearMonth other The value to compare this year/month with.
Returns
Type Description
Boolean True if the given value is another year/month equal to this one; false otherwise.

Equals(Object)

Compares two YearMonth values for equality. See the type documentation for a description of equality semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
Object obj The object to compare this year/month with.
Returns
Type Description
Boolean True if the given value is another year/month equal to this one; false otherwise.
Overrides
System.ValueType.Equals(System.Object)

GetHashCode()

Returns a hash code for this year/month. See the type documentation for a description of equality semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public override int GetHashCode()
Returns
Type Description
Int32 A hash code for this value.
Overrides
System.ValueType.GetHashCode()

OnDayOfMonth(Int32)

Returns a LocalDate with the year/month of this value, and the given day of month.
Since 3.0.x
Availability netstandard2.0
Declaration
public LocalDate OnDayOfMonth(int day)
Parameters
Type Name Description
Int32 day The day within the month.
Returns
Type Description
LocalDate The result of combining this year and month with day.
Exceptions
Type Condition
ArgumentOutOfRangeException day does not fall within the month represented by this value.

ToDateInterval()

Returns a DateInterval covering the month represented by this value.
Since 3.0.x
Availability netstandard2.0
Declaration
public DateInterval ToDateInterval()
Returns
Type Description
DateInterval A DateInterval covering the month represented by this value.
Sample snippet
using NodaTime;
using System;

YearMonth yearMonth = new YearMonth(2019, 5);
DateInterval interval = yearMonth.ToDateInterval();
Console.WriteLine(interval.Start);
Console.WriteLine(interval.End);

Output:

Wednesday, 01 May 2019
Friday, 31 May 2019

ToString(String, IFormatProvider)

Formats the value of the current instance using the specified pattern.
Since 3.0.x
Availability netstandard2.0
Declaration
public string ToString(string patternText, IFormatProvider formatProvider)
Parameters
Type Name Description
String patternText The System.String specifying the pattern to use, or null to use the default format pattern ("D").
IFormatProvider formatProvider The System.IFormatProvider to use when formatting the value, or null to use the current thread's culture to obtain a format provider.
Returns
Type Description
String A System.String containing the value of the current instance in the specified format.

Operators

Equality(YearMonth, YearMonth)

Compares two YearMonth values for equality. See the type documentation for a description of equality semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator ==(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs The first value to compare
YearMonth rhs The second value to compare
Returns
Type Description
Boolean True if the two year/month values are the same and in the same calendar; false otherwise

GreaterThan(YearMonth, YearMonth)

Compares two YearMonth values to see if the left one is strictly later than the right one. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator>(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs First operand of the comparison
YearMonth rhs Second operand of the comparison
Returns
Type Description
Boolean true if the lhs is strictly later than rhs, false otherwise.
Exceptions
Type Condition
ArgumentException The calendar system of rhs is not the same as the calendar of lhs.

GreaterThanOrEqual(YearMonth, YearMonth)

Compares two YearMonth values to see if the left one is later than or equal to the right one. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator >=(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs First operand of the comparison
YearMonth rhs Second operand of the comparison
Returns
Type Description
Boolean true if the lhs is later than or equal to rhs, false otherwise.
Exceptions
Type Condition
ArgumentException The calendar system of rhs is not the same as the calendar of lhs.

Inequality(YearMonth, YearMonth)

Compares two YearMonth values for inequality. See the type documentation for a description of equality semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator !=(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs The first value to compare
YearMonth rhs The second value to compare
Returns
Type Description
Boolean False if the two year/month values are the same and in the same calendar; true otherwise

LessThan(YearMonth, YearMonth)

Compares two YearMonth values to see if the left one is strictly earlier than the right one. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator <(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs First operand of the comparison
YearMonth rhs Second operand of the comparison
Returns
Type Description
Boolean true if the lhs is strictly earlier than rhs, false otherwise.
Exceptions
Type Condition
ArgumentException The calendar system of rhs is not the same as the calendar of lhs.

LessThanOrEqual(YearMonth, YearMonth)

Compares two YearMonth values to see if the left one is earlier than or equal to the right one. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
public static bool operator <=(YearMonth lhs, YearMonth rhs)
Parameters
Type Name Description
YearMonth lhs First operand of the comparison
YearMonth rhs Second operand of the comparison
Returns
Type Description
Boolean true if the lhs is earlier than or equal to rhs, false otherwise.
Exceptions
Type Condition
ArgumentException The calendar system of rhs is not the same as the calendar of lhs.

Explicit Interface Implementations

IComparable.CompareTo(Object)

Implementation of System.IComparable.CompareTo(System.Object) to compare two YearMonth values. See the type documentation for a description of ordering semantics.
Since 3.0.x
Availability netstandard2.0
Declaration
int IComparable.CompareTo(object obj)
Parameters
Type Name Description
Object obj The object to compare this value with.
Returns
Type Description
Int32 The result of comparing this YearMonth with another one. If obj is null, this method returns a value greater than 0.
Remarks
This uses explicit interface implementation to avoid it being called accidentally. The generic implementation should usually be preferred.
Exceptions
Type Condition
ArgumentException obj is non-null but does not refer to an instance of YearMonth, or refers to a value in a different calendar system.

IXmlSerializable.GetSchema()

Since 3.0.x
Availability netstandard2.0
Declaration
XmlSchema IXmlSerializable.GetSchema()
Returns
Type Description
XmlSchema

IXmlSerializable.ReadXml(XmlReader)

Since 3.0.x
Availability netstandard2.0
Declaration
void IXmlSerializable.ReadXml(XmlReader reader)
Parameters
Type Name Description
XmlReader reader

IXmlSerializable.WriteXml(XmlWriter)

Since 3.0.x
Availability netstandard2.0
Declaration
void IXmlSerializable.WriteXml(XmlWriter writer)
Parameters
Type Name Description
XmlWriter writer

Implements

System.IEquatable<T>
System.IComparable<T>
System.IComparable
System.IFormattable
System.Xml.Serialization.IXmlSerializable