A period refers to a continuous time span with a well-defined start and end. It represents a range rather than a single event and serves as a frame of reference by providing structure.
Examples:
Q1 2025: January 1 – March 31, 2025FY2025: April 1, 2024 – March 31, 2025Week 5 of 2025: January 29 – February 4, 2025
In Chrononuensis, a period is represented by the interface IPeriod.
Types implementing IPeriod
The following types implement the IPeriod interface:
- Century
- Decade
- Year
- YearSemester
- YearQuarter
- YearWeek
- YearDay
Each of these types provides a structured way to represent specific time intervals.
Properties
All types implementing IPeriod expose the following properties:
Days
Returns the total number of days within the period.
var yearQuarter = YearQuarter.Parse("2025-Q1");
Assert.That(yearQuarter.Days, Is.EqualTo(31 + 28 + 31));
In this example, the first quarter of 2025 spans 31 days in January, 28 days in February, and 31 days in March (equal to 90 days).
FirstDate
Returns the first date of the period.
var yearQuarter = YearQuarter.Parse("2025-Q1");
Assert.That(yearQuarter.FirstDate, Is.EqualTo(new DateOnly(2025, 1, 1)));
The first date of Q1 2025 is January 1, 2025.
LastDate
Returns the last date of the period.
var yearQuarter = YearQuarter.Parse("2025-Q1");
Assert.That(yearQuarter.LastDate, Is.EqualTo(new DateOnly(2025, 3, 31)));
The last date of Q1 2025 is March 31, 2025.
LowerBound
Represents the lower bound of the period, defined as a close/open interval, typically at the start of FirstDate
var yearQuarter = YearQuarter.Parse("2025-Q1");
Assert.That(yearQuarter.LowerBound, Is.EqualTo(new DateTime(2025, 1, 1, 0, 0, 0)));
The lower bound of Q1 2025 starts on January 1, 2025, at midnight.
UpperBound
Represents the upper bound of the period, defined as a close/open interval, typically at the start of the day following LastDate.
var yearQuarter = YearQuarter.Parse("2025-Q1");
Assert.That(yearQuarter.UpperBound, Is.EqualTo(new DateTime(2025, 4, 1, 0, 0, 0)));
The upper bound of Q1 2025 is April 1, 2025, at midnight, meaning the period runs from January 1, 2025 (inclusive) to April 1, 2025 (exclusive).
