Calendar Dates

A new type of the chrono extension in C++20 is a calendar date. C++20 supports various ways to create a calendar date and interact with them. First of all: What is a calendar date?

• A calendar date is a date that consists of a year, a month, and a day. Consequently, C++20 has a specific data type std::chrono::year_month_day. C++20 has way more to offer. The following table should give you the first overview of calendar-date types before I show you various use-cases.

Type	Description
std::chrono::last_spec	Indicates the last day or weekday of a month
std::chrono::day	Represents a day of a month
std::chrono::month	Represents a month of a year
std::chrono::year	Represents a year in the Gregorian calendar
std::chrono::weekday	Represents a day of the week in the Gregorian calendar
std::chrono::weekday_indexed	Represents the nth weekday of a month
std::chrono::weekday_last	Represents the last weekday of a month
std::chrono::month_day	Represents a specific day of a specific month
std::chrono::month_day_last	Represents the last day of a specific month
std::chrono::month_weekday	Represents the nth weekday of a specific month
std::chrono::month_weekday_last	Represents the last weekday of a specific month
std::chrono::year_month	Represents a specific month of a specific year
std::chrono::year_month_day	Represents a specific year, month, and day
std::chrono::year_month_day_last	Represents the last day of a specific year and month
std::chrono::year_month_weekday	Represents the nth weekday of a specific year and month
std::chrono::year_month_day_weekday_last	Represents the last weekday of a specific years and month
std::chrono::operator /	Creates a date of the Gregorian calendar

Let me start simple and create a few calendar dates.

Create calendar dates

The following program shows various ways to create calendar-related dates.