NCrontab 3.4.0

dotnet add package NCrontab --version 3.4.0
                    
NuGet\Install-Package NCrontab -Version 3.4.0
                    
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="NCrontab" Version="3.4.0" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="NCrontab" Version="3.4.0" />
                    
Directory.Packages.props
<PackageReference Include="NCrontab" />
                    
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 NCrontab --version 3.4.0
                    
#r "nuget: NCrontab, 3.4.0"
                    
#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 NCrontab@3.4.0
                    
#: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=NCrontab&version=3.4.0
                    
Install as a Cake Addin
#tool nuget:?package=NCrontab&version=3.4.0
                    
Install as a Cake Tool

NCrontab: Crontab for .NET

Build Status NuGet

NCrontab is a library written in C# targeting .NET Standard Library 1.0 and that provides the following facilities:

  • Parsing of crontab expressions
  • Formatting of crontab expressions
  • Calculation of occurrences of time based on a crontab schedule

This library does not provide any scheduler or is not a scheduling facility like cron from Unix platforms. What it provides is parsing, formatting and an algorithm to produce occurrences of time based on a give schedule expressed in the crontab format:

* * * * *
- - - - -
| | | | |
| | | | +----- day of week (0 - 6) (Sunday=0)
| | | +------- month (1 - 12)
| | +--------- day of month (1 - 31)
| +----------- hour (0 - 23)
+------------- min (0 - 59)

or a six-part format that allows for seconds:

* * * * * *
- - - - - -
| | | | | |
| | | | | +--- day of week (0 - 6) (Sunday=0)
| | | | +----- month (1 - 12)
| | | +------- day of month (1 - 31)
| | +--------- hour (0 - 23)
| +----------- min (0 - 59)
+------------- sec (0 - 59)

Star (*) in the value field above means all legal values as in parentheses for that column. The value column can have a * or a list of elements separated by commas. An element is either a number in the ranges shown above or two numbers in the range separated by a hyphen (meaning an inclusive range). For more, see CrontabExpression.

The default format parsed by CrontabSchedule.Parse is the five-part cron format. In order to use the six-part format that includes seconds, pass a CrontabSchedule.ParseOptions to Parse with IncludingSeconds set to true. For example:

var s = CrontabSchedule.Parse("0,30 * * * * *",
                              new CrontabSchedule.ParseOptions
                              {
                                  IncludingSeconds = true
                              });

Below is an example in IronPython of how to use CrontabSchedule class from NCrontab to generate occurrences of the schedule 0 12 * */2 Mon (meaning, 12:00 PM on Monday of every other month, starting with January) throughout the year 2000:

IronPython 1.1 (1.1) on .NET 2.0.50727.1434
Copyright (c) Microsoft Corporation. All rights reserved.
>>> import clr
>>> clr.AddReferenceToFileAndPath(r'C:\NCrontab\bin\Release\NCrontab.dll')
>>> from System import DateTime
>>> from NCrontab import CrontabSchedule
>>> s = CrontabSchedule.Parse('0 12 * */2 Mon')
>>> start = DateTime(2000, 1, 1)
>>> end = start.AddYears(1)
>>> occurrences = s.GetNextOccurrences(start, end)
>>> print '\n'.join([t.ToString('ddd, dd MMM yyyy HH:mm') for t in occurrences])
Mon, 03 Jan 2000 12:00
Mon, 10 Jan 2000 12:00
Mon, 17 Jan 2000 12:00
Mon, 24 Jan 2000 12:00
Mon, 31 Jan 2000 12:00
Mon, 06 Mar 2000 12:00
Mon, 13 Mar 2000 12:00
Mon, 20 Mar 2000 12:00
Mon, 27 Mar 2000 12:00
Mon, 01 May 2000 12:00
Mon, 08 May 2000 12:00
Mon, 15 May 2000 12:00
Mon, 22 May 2000 12:00
Mon, 29 May 2000 12:00
Mon, 03 Jul 2000 12:00
Mon, 10 Jul 2000 12:00
Mon, 17 Jul 2000 12:00
Mon, 24 Jul 2000 12:00
Mon, 31 Jul 2000 12:00
Mon, 04 Sep 2000 12:00
Mon, 11 Sep 2000 12:00
Mon, 18 Sep 2000 12:00
Mon, 25 Sep 2000 12:00
Mon, 06 Nov 2000 12:00
Mon, 13 Nov 2000 12:00
Mon, 20 Nov 2000 12:00
Mon, 27 Nov 2000 12:00

Below is the same example in F# Interactive (fsi.exe):

Microsoft (R) F# 2.0 Interactive build 4.0.40219.1
Copyright (c) Microsoft Corporation. All Rights Reserved.

For help type #help;;

> #r "NCrontab.dll"
-
- open NCrontab
- open System
-
- let schedule = CrontabSchedule.Parse("0 12 * */2 Mon")
- let startDate = DateTime(2000, 1, 1)
- let endDate = startDate.AddYears(1)
-
- let occurrences = schedule.GetNextOccurrences(startDate, endDate)
- occurrences |> Seq.map (fun t -> t.ToString("ddd, dd MMM yyy HH:mm"))
-             |> String.concat "\n"
-             |> printfn "%s";;

--> Referenced 'C:\NCrontab\bin\Release\NCrontab.dll'

Mon, 03 Jan 2000 12:00
Mon, 10 Jan 2000 12:00
Mon, 17 Jan 2000 12:00
Mon, 24 Jan 2000 12:00
Mon, 31 Jan 2000 12:00
Mon, 06 Mar 2000 12:00
Mon, 13 Mar 2000 12:00
Mon, 20 Mar 2000 12:00
Mon, 27 Mar 2000 12:00
Mon, 01 May 2000 12:00
Mon, 08 May 2000 12:00
Mon, 15 May 2000 12:00
Mon, 22 May 2000 12:00
Mon, 29 May 2000 12:00
Mon, 03 Jul 2000 12:00
Mon, 10 Jul 2000 12:00
Mon, 17 Jul 2000 12:00
Mon, 24 Jul 2000 12:00
Mon, 31 Jul 2000 12:00
Mon, 04 Sep 2000 12:00
Mon, 11 Sep 2000 12:00
Mon, 18 Sep 2000 12:00
Mon, 25 Sep 2000 12:00
Mon, 06 Nov 2000 12:00
Mon, 13 Nov 2000 12:00
Mon, 20 Nov 2000 12:00
Mon, 27 Nov 2000 12:00

Below is the same example in C# Interactive (csi.exe):

Microsoft (R) Visual C# Interactive Compiler version 1.2.0.60317
Copyright (C) Microsoft Corporation. All rights reserved.

Type "#help" for more information.
> #r "NCrontab.dll"
> using NCrontab;
> var s = CrontabSchedule.Parse("0 12 * */2 Mon");
> var start = new DateTime(2000, 1, 1);
> var end = start.AddYears(1);
> var occurrences = s.GetNextOccurrences(start, end);
> Console.WriteLine(string.Join(Environment.NewLine,
.     from t in occurrences
.     select $"{t:ddd, dd MMM yyyy HH:mm}"));
Mon, 03 Jan 2000 12:00
Mon, 10 Jan 2000 12:00
Mon, 17 Jan 2000 12:00
Mon, 24 Jan 2000 12:00
Mon, 31 Jan 2000 12:00
Mon, 06 Mar 2000 12:00
Mon, 13 Mar 2000 12:00
Mon, 20 Mar 2000 12:00
Mon, 27 Mar 2000 12:00
Mon, 01 May 2000 12:00
Mon, 08 May 2000 12:00
Mon, 15 May 2000 12:00
Mon, 22 May 2000 12:00
Mon, 29 May 2000 12:00
Mon, 03 Jul 2000 12:00
Mon, 10 Jul 2000 12:00
Mon, 17 Jul 2000 12:00
Mon, 24 Jul 2000 12:00
Mon, 31 Jul 2000 12:00
Mon, 04 Sep 2000 12:00
Mon, 11 Sep 2000 12:00
Mon, 18 Sep 2000 12:00
Mon, 25 Sep 2000 12:00
Mon, 06 Nov 2000 12:00
Mon, 13 Nov 2000 12:00
Mon, 20 Nov 2000 12:00
Mon, 27 Nov 2000 12:00

Below is the same example in C# using dotnet-script:

> #r "nuget:NCrontab"
> using NCrontab;
> var s = CrontabSchedule.Parse("0 12 * */2 Mon");
> var start = new DateTime(2000, 1, 1);
> var end = start.AddYears(1);
> var occurrences = s.GetNextOccurrences(start, end);
> Console.WriteLine(string.Join(Environment.NewLine,
*     from t in occurrences
*     select $"{t:ddd, dd MMM yyyy HH:mm}"));
Mon, 03 Jan 2000 12:00
Mon, 10 Jan 2000 12:00
Mon, 17 Jan 2000 12:00
Mon, 24 Jan 2000 12:00
Mon, 31 Jan 2000 12:00
Mon, 06 Mar 2000 12:00
Mon, 13 Mar 2000 12:00
Mon, 20 Mar 2000 12:00
Mon, 27 Mar 2000 12:00
Mon, 01 May 2000 12:00
Mon, 08 May 2000 12:00
Mon, 15 May 2000 12:00
Mon, 22 May 2000 12:00
Mon, 29 May 2000 12:00
Mon, 03 Jul 2000 12:00
Mon, 10 Jul 2000 12:00
Mon, 17 Jul 2000 12:00
Mon, 24 Jul 2000 12:00
Mon, 31 Jul 2000 12:00
Mon, 04 Sept 2000 12:00
Mon, 11 Sept 2000 12:00
Mon, 18 Sept 2000 12:00
Mon, 25 Sept 2000 12:00
Mon, 06 Nov 2000 12:00
Mon, 13 Nov 2000 12:00
Mon, 20 Nov 2000 12:00
Mon, 27 Nov 2000 12:00

Some complex schedules cannot be expressed in a single crontab expression so NCrontab can produce distinct occurrences given a sequence of CrontabSchedule instances. In the C# example below, two schedules are merged to produce a single set of occurrences over a week. The first schedule occurs every 6 hours on weekdays while the second occurs every 12 hours on weekends.

Microsoft (R) Visual C# Interactive Compiler version 1.2.0.60317
Copyright (C) Microsoft Corporation. All rights reserved.

Type "#help" for more information.
> using NCrontab;
> var s1 = CrontabSchedule.Parse("0 */6 * * Mon-Fri");
> var s2 = CrontabSchedule.Parse("0 */12 * * Sat,Sun");
> var s = new[] { s1, s2 };
> var start = new DateTime(2000, 1, 1);
> var end = start.AddDays(7);
> var occurrences = s.GetNextOccurrences(start, end);
> // `Sat, 01 Jan 2000 10:00` won't appear because `start` is exclusive
> Console.WriteLine(string.Join(Environment.NewLine,
.     from t in occurrences
.     select $"{t:ddd, dd MMM yyyy HH:mm}"));
Sat, 01 Jan 2000 12:00
Sun, 02 Jan 2000 00:00
Sun, 02 Jan 2000 12:00
Mon, 03 Jan 2000 00:00
Mon, 03 Jan 2000 06:00
Mon, 03 Jan 2000 12:00
Mon, 03 Jan 2000 18:00
Tue, 04 Jan 2000 00:00
Tue, 04 Jan 2000 06:00
Tue, 04 Jan 2000 12:00
Tue, 04 Jan 2000 18:00
Wed, 05 Jan 2000 00:00
Wed, 05 Jan 2000 06:00
Wed, 05 Jan 2000 12:00
Wed, 05 Jan 2000 18:00
Thu, 06 Jan 2000 00:00
Thu, 06 Jan 2000 06:00
Thu, 06 Jan 2000 12:00
Thu, 06 Jan 2000 18:00
Fri, 07 Jan 2000 00:00
Fri, 07 Jan 2000 06:00
Fri, 07 Jan 2000 12:00
Fri, 07 Jan 2000 18:00

If one or more schedules produce the same occurrence then only one of them if returned.

Merging Schedules

NCrontab can merge the timeline of one or more schedules. This can sometimes come handy when it's impossible to express a schedule with a single crontab expression like every 6 hours from 9 AM to 5 PM, on weekdays, but at noon on weekends. By breaking it up into two schedules:

  • 0 12 * * Sat-Sun: at noon on weekends
  • 0 9-17/6 * * Mon-Fri: every 6 hours from 9 AM to 5 PM on weekdays

you can merge them to produce a single timeline:

using System;
using NCrontab;

var start = new DateTime(2000, 1, 1);
var end = start.AddYears(1);
var schedules = new[]
{
    CrontabSchedule.Parse("0 12 * * Sat-Sun"),
    CrontabSchedule.Parse("0 9-17/6 * * Mon-Fri")
};
var occurrences = schedules.GetNextOccurrences(start, end);
Console.WriteLine(string.Join(Environment.NewLine,
                              from t in occurrences
                              select $"{t:ddd, dd MMM yyyy HH:mm}"));

The output from a run will:

Sat, 01 Jan 2000 12:00
Sun, 02 Jan 2000 12:00
Mon, 03 Jan 2000 09:00
Mon, 03 Jan 2000 12:00
Mon, 03 Jan 2000 15:00
Tue, 04 Jan 2000 09:00
Tue, 04 Jan 2000 12:00
Tue, 04 Jan 2000 15:00
Wed, 05 Jan 2000 09:00
Wed, 05 Jan 2000 12:00
Wed, 05 Jan 2000 15:00
Thu, 06 Jan 2000 09:00
Thu, 06 Jan 2000 12:00
Thu, 06 Jan 2000 15:00
Fri, 07 Jan 2000 09:00
Fri, 07 Jan 2000 12:00
Fri, 07 Jan 2000 15:00
Sat, 08 Jan 2000 12:00
Sun, 09 Jan 2000 12:00
...

If two or more schedules produce the same occurrence then only one of them is returned.


This product includes software developed by the OpenSymphony Group.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  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. 
.NET Core netcoreapp1.0 was computed.  netcoreapp1.1 was computed.  netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard1.0 is compatible.  netstandard1.1 was computed.  netstandard1.2 was computed.  netstandard1.3 was computed.  netstandard1.4 was computed.  netstandard1.5 was computed.  netstandard1.6 was computed.  netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net35 is compatible.  net40 was computed.  net403 was computed.  net45 was computed.  net451 was computed.  net452 was computed.  net46 was computed.  net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen30 was computed.  tizen40 was computed.  tizen60 was computed. 
Universal Windows Platform uap was computed.  uap10.0 was computed. 
Windows Phone wp8 was computed.  wp81 was computed.  wpa81 was computed. 
Windows Store netcore was computed.  netcore45 was computed.  netcore451 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (141)

Showing the top 5 NuGet packages that depend on NCrontab:

Package Downloads
Umbraco.Cms.Infrastructure

Contains the infrastructure assembly needed to run Umbraco CMS.

OrchardCore

Orchard Core Framework is an application framework for building modular, multi-tenant applications on ASP.NET Core. Implementation of OrchardCore modular, multi-tenant ShellHost

OrchardCore.Infrastructure

Orchard Core CMS is a Web Content Management System (CMS) built on top of the Orchard Core Framework. Implementation for OrchardCoreCMS Infrastructure

OrchardCore.Application.Targets

Orchard Core Framework is an application framework for building modular, multi-tenant applications on ASP.NET Core. Converts the application into a modular application.

HQ

This package contains the full-stack build for HQ.io.

GitHub repositories (22)

Showing the top 20 popular GitHub repositories that depend on NCrontab:

Repository Stars
OrchardCMS/OrchardCore
Orchard Core is an open-source modular and multi-tenant application framework built with ASP.NET Core, and a content management system (CMS) built on top of that framework.
kurrent-io/KurrentDB
KurrentDB is a database that's engineered for modern software applications and event-driven architectures. Its event-native design simplifies data modeling and preserves data integrity while the integrated streaming engine solves distributed messaging challenges and ensures data consistency.
umbraco/Umbraco-CMS
Umbraco is a free and open source .NET content management system helping you deliver delightful digital experiences.
simplcommerce/SimplCommerce
A simple, cross platform, modulith ecommerce system built on .NET
Ombi-app/Ombi
Want a Movie or TV Show on Plex/Emby/Jellyfin? Use Ombi!
projectkudu/kudu
Kudu is the engine behind git/hg deployments, WebJobs, and various other features in Azure Web Sites. It can also run outside of Azure.
SciSharp/BotSharp
AI Multi-Agent Framework in .NET
smartstore/SmartStoreNET
Open Source ASP.NET MVC Enterprise eCommerce Shopping Cart Solution
Azure/durabletask
Durable Task Framework allows users to write long running persistent workflows in C# using the async/await capabilities.
HangfireIO/Cronos
A fully-featured .NET library for working with Cron expressions. Built with time zones in mind and intuitively handles daylight saving time transitions
sjkp/letsencrypt-siteextension
Azure Web App Site Extension for easy installation and configuration of Let's Encrypt issued SSL certifcates for custom domain names.
brthor/Gofer.NET
Easy C# API for Distributed Background Tasks/Jobs for .NET Core.
pnp/PnP-Tools
Scripts and tools for Office 365 and SharePoint - More for IT Pro's
SaiGonSoftware/Awesome-CMS-Core
Awesome CMS Core is an open source CMS built using ASP.Net Core & ReactJS with module seperation concern in mind and provide lastest trend of technology like .Net Core, React, Webpack, SASS, Background Job, Message Queue.
AAEmu/AAEmu
A server software for ArcheAge written in .Net Core
sthewissen/Mynt
An Azure Functions-based crypto currency trading bot; featuring 10 exchanges, 25 indicators, custom strategy support, backtester and more
yuzd/Hangfire.Core.Extend
在1.6.5基础上给dashbord增加了搜索功能,增加在dashbord上手动添加job,提供对外SDK添加job
weibaohui/blazork8s
manage k8s using c# blazor enhance by chatgpt ,try something new !使用blazor技术开发的内置OpenAI GPT的k8s 管理界面
csharpfritz/Fritz.StreamTools
Handy tools for managing my live stream, built with ASP.NET Core
microsoft/sql-data-warehouse-samples
Snippets and samples for Azure SQL Data Warehouse
Version Downloads Last Updated
3.4.0 0 9/13/2025
3.3.3 8,236,984 8/31/2023
3.3.1 26,237,868 2/12/2019
3.3.0 16,758,490 12/21/2016
3.2.0 151,115 10/20/2016
3.1.0 557,450 12/11/2015
3.0.0 5,614 12/9/2015
2.0.0 1,592,586 8/18/2014
1.0.0 299,054 1/29/2011