---
title: DateRange
summary: API reference for DateRange.
status: draft
owner: saif-docgen
last_reviewed: 2026-09-15
library: SAIF.Framework.Common
reference_type: package
---

# DateRange

Concrete, mutable begin/end date-pair implementation of `IDateRange`, with value-equality semantics, string round-tripping, and a shared empty-range singleton.

## Purpose
- Concrete, mutable begin/end date-pair implementation of `IDateRange`, with value-equality semantics, string round-tripping, and a shared empty-range singleton.

## Context
- Namespace: `SAIF.Common`
- Assembly/package: `SAIF.Framework.Common`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| BeginDate | `public DateTime BeginDate { get; set; }` | The inclusive start of the range. |
| EndDate | `public DateTime EndDate { get; set; }` | The inclusive end of the range. |
| DefaultToStringDelimiter | `public const string DefaultToStringDelimiter = "-"` | Default separator used between the two dates when formatting with `ToString`. |
| DateRange() | `public DateRange()` | Parameterless constructor; sets `BeginDate` to `DateTime.MinValue` and `EndDate` to `DateTime.MaxValue` (an open-ended range), not the `DateTime` default. |
| DateRange(DateTime beginDate) | `public DateRange(DateTime beginDate)` | Constructs a range starting at `beginDate` with `EndDate` set to `DateTime.MaxValue` (open-ended). |
| DateRange(DateTime beginDate, DateTime endDate) | `public DateRange(DateTime beginDate, DateTime endDate)` | Constructs a range from explicit begin/end dates; if `endDate` is `DateTime.MinValue` it is coerced to `DateTime.MaxValue`. ([BR-033](../../business-rules.md#br-033-an-end-date-supplied-as-datetime.minvalue-is-reinterpreted-as-no-end-date-and-coerced-to-datetime.maxvalue)) |
| DateRange(IDateRange dateRange) | `public DateRange(IDateRange dateRange)` | Copy constructor from any `IDateRange` implementation. |
| operator ==(DateRange, IDateRange) | `public static bool operator ==(DateRange d1, IDateRange d2)` | Compares two ranges by `BeginDate`/`EndDate` value equality; dereferences both operands directly, so a null `d1` or `d2` raises a `NullReferenceException` rather than being handled. |
| operator !=(DateRange, IDateRange) | `public static bool operator !=(DateRange d1, IDateRange d2)` | Inverse of the equality operator; shares the same null-dereference behavior. |
| Equals(object) | `public override bool Equals(object obj)` | Structural equality against another `IDateRange`; delegates to the equality operator. |
| GetHashCode() | `public override int GetHashCode()` | Combines `BeginDate` and `EndDate` hash codes. |
| ToString(string delimiter) | `public string ToString(string delimiter = DefaultToStringDelimiter)` | Formats as `"{BeginDate}{delimiter}{EndDate}"` using each date's `ToShortDateString()`. |
| ToString(string beginDateFormat, string endDateFormat, string delimiter) | `public string ToString(string beginDateFormat, string endDateFormat, string delimiter = DefaultToStringDelimiter)` | Formats each date with its own supplied format string. |
| Parse(string date, string delimiter) | `public static DateRange Parse(string date, string delimiter = DefaultToStringDelimiter)` | Static factory that splits `date` on `delimiter` and parses each side as a `DateTime`, returning a populated `DateRange`; any exception during parsing is swallowed and an empty `DateRange()` is returned instead. ([BR-031](../../business-rules.md#br-031-parsing-a-malformed-date-range-string-never-throws-%E2%80%94-it-silently-yields-the-unbounded-default-range)) |
| Empty | `public static DateRange Empty { get; }` | Shared, effectively read-only instance representing an unset/empty range for defaulting purposes. |


## Sources
- `Common/SAIF.Common/Classes/DateRange.cs`