StarThrower.DateTimeUtilities 2.0.0

.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher. 
dotnet add package StarThrower.DateTimeUtilities --version 2.0.0
                    


                    

                
NuGet\Install-Package StarThrower.DateTimeUtilities -Version 2.0.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="StarThrower.DateTimeUtilities" Version="2.0.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="StarThrower.DateTimeUtilities" Version="2.0.0" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="StarThrower.DateTimeUtilities" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add StarThrower.DateTimeUtilities --version 2.0.0
                    


                    

                
#r "nuget: StarThrower.DateTimeUtilities, 2.0.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package StarThrower.DateTimeUtilities@2.0.0
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=StarThrower.DateTimeUtilities&version=2.0.0
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=StarThrower.DateTimeUtilities&version=2.0.0
                    


                            Install as a Cake Tool

StarThrower.DateTimeUtilities

Date and time helper methods for common calculations, formatting, and manipulation operations.

StarThrower.DateTimeUtilities provides DTUtil, a static class of helpers for formatting DateTime values, computing differences between dates in various units, and converting to/from ISO 8601 strings.

Installation

dotnet add package StarThrower.DateTimeUtilities

DTUtil

Method Description
ToMmddyyString(DateTime dt) Returns dt formatted as MMDDYY (e.g. 2026-06-09 → "060926").
DateDiff(DateInterval interval, DateTime date1, DateTime date2) Returns date2 - date1 expressed in the units specified by interval (Year, Month, Weekday, Day, Hour, Minute, or Second). Corrects rounding/calendar issues present in the classic VB DateDiff function.
DateTimeToIso8601(DateTime dt) Obsolete — use new DateTimeOffset(DateTime.SpecifyKind(dt, DateTimeKind.Utc)).ToString("o", CultureInfo.InvariantCulture) instead. Converts dt to an ISO 8601 string in the form YYYY-MM-DDTHH:MM:SS.fffffff+00:00 (always reports a +00:00 time zone designator, regardless of dt.Kind).
Iso8601ToDateTime(string? iso) Obsolete — use DateTimeOffset.Parse(iso, CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal \| DateTimeStyles.AdjustToUniversal).UtcDateTime instead. Parses an ISO 8601 string back into a DateTime, converting any time zone designator (+/- offset or Z) present in the input to UTC.
TruncateToSeconds(DateTime dt) Returns a new DateTime with the same year, month, day, hour, minute, and second as dt, with any sub-second component discarded (floored, not rounded).
RoundToSeconds(DateTime dt) Obsolete — use TruncateToSeconds(DateTime) instead. Despite the name, this method truncates rather than rounds; it is kept only for backward compatibility. 
using StarThrower.DateTimeUtilities;

DateTime now = DateTime.Now;

string mmddyy = DTUtil.ToMmddyyString(now); // e.g. "060926"

long monthsApart = DTUtil.DateDiff(DateInterval.Month, new DateTime(2025, 1, 15), new DateTime(2026, 6, 9));

string iso = new DateTimeOffset(DateTime.SpecifyKind(now, DateTimeKind.Utc)).ToString("o", CultureInfo.InvariantCulture);
// e.g. "2026-06-09T14:30:45.1234567+00:00"
DateTime parsed = DateTimeOffset.Parse(iso, CultureInfo.InvariantCulture,
    DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal).UtcDateTime;

DateTime truncated = DTUtil.TruncateToSeconds(now); // milliseconds dropped

DateInterval

public enum DateInterval
{
    Year = 0,
    Month = 1,
    Weekday = 2,
    Day = 3,
    Hour = 4,
    Minute = 5,
    Second = 6
}

Used by DateDiff to specify the unit of the result. Weekday returns whole weeks elapsed (TotalDays / 7), not a day-of-week name.

Usage Notes

  • DateTimeToIso8601 always treats its input as UTC and writes a +00:00 time zone designator, regardless of the input DateTime's Kind. Iso8601ToDateTime correctly converts whatever offset (or Z) is present in the input to UTC, so round-tripping is safe provided the original DateTime was in fact UTC.
  • DateDiff(DateInterval.Year, ...) and DateDiff(DateInterval.Month, ...) use calendar-aware arithmetic (accounting for month/day boundaries), while Day, Hour, Minute, and Second are based on the total elapsed TimeSpan, truncated toward zero.

Dependencies

License

Copyright © 2026 Stephen Elmer. Licensed under the MIT License.

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
2.0.0 94 7/4/2026

See https://github.com/StephenElmer/starthrower-utilities/releases