Displaying the build date

Question

I currently have an app displaying the build number in its title window   That s well and good except it means nothing to most of the users  who want to know if they have the latest build - they tend to refer to it as  last Thursday s  rather than build 1 0 8 4321   The plan is to put the build date there instead - So  App built on 21 10 2009  for example   I m struggling to find a programmatic way to pull the build date out as a text string for use like this   For the build number  I used   Assembly GetExecutingAssembly   GetName   Version ToString     after defining how those came up   I d like something like that for the compile date  and time  for bonus points    Pointers here much appreciated  excuse pun if appropriate   or neater solutions

User · Answer

I used Abdurrahim s suggestion  However  it seemed to give a weird time format and also added the abbreviation for the day as part of the build date  example  Sun 12 24 2017 13 21 05 43  I only needed just the date so I had to eliminate the rest using substring   After adding the echo  date   time   gt     ProjectDir  Resources BuildDate txt to the pre-build event  I just did the following   string strBuildDate   YourNamespace Properties Resources BuildDate  string strTrimBuildDate   strBuildDate Substring 4  Remove 10     The good news here is that it worked

User · Answer

I just added pre-build event command  powershell -Command Get-Date -Format  yyyy-MM-ddTHH mm sszzz   gt  Resources BuildDateTime txt  in the project properties to generate a resource file that is then easy to read from the code

User · Answer

I m not sure  but maybe the Build Incrementer helps

User · Answer

Lots of great answers here but I feel like I can add my own because of simplicity  performance  comparing to resource-related solutions  cross platform  works with Net Core too  and avoidance of any 3rd party tool  Just add this msbuild target to the csproj    lt Target Name  Date  BeforeTargets  CoreCompile  gt       lt WriteLinesToFile File    IntermediateOutputPath gen cs  Lines  static partial class Builtin   public static long CompileTime      System DateTime   UtcNow Ticks   3B    Overwrite  true    gt       lt ItemGroup gt           lt Compile Include    IntermediateOutputPath gen cs    gt       lt  ItemGroup gt   lt  Target gt    and now you have Builtin CompileTime or new DateTime Builtin CompileTime  DateTimeKind Utc  if you need it that way   ReSharper is not gonna like it  You can ignore him or add a partial class to the project too but it works anyway

User · Answer

Regarding the technique of pulling build date version info from the bytes of an assembly PE header  Microsoft has changed the default build parameters beginning with Visual Studio 15 4   The new default includes deterministic compilation  which makes a valid timestamp and automatically incremented version numbers a thing of the past   The timestamp field is still present but it gets filled with a permanent value that is a hash of something or other  but not any indication of the build time     Some detailed background here  For those who prioritize a useful timestamp over deterministic compilation  there is a way to override the new default   You can include a tag in the  csproj file of the assembly of interest as follows      lt PropertyGroup gt                   lt Deterministic gt false lt  Deterministic gt     lt  PropertyGroup gt    Update  I endorse the T4 text template solution described in another answer here   I used it  to solve my issue cleanly without losing the benefit of deterministic compilation   One caution about it is that Visual Studio only runs the T4 compiler when the  tt file is saved  not at build time   This can be awkward if you exclude the  cs result from source control  since you expect it to be generated  and another developer checks out the code   Without resaving  they won t have the  cs file   There is a package on nuget  I think called AutoT4  that makes T4 compilation part of every build   I have not yet confronted the solution to this during production deployment  but I expect something similar to make it right

User · Answer

You could launch an extra step in the build process that writes a date stamp to a file which can then be displayed   On the projects properties tab look at the build events tab  There is an option to execute a pre or post build command

User · Answer

A small update on the  New Way  answer from Jhon   You need to build the path instead of using the CodeBase string when working with ASP NET MVC      var codeBase   assembly GetName   CodeBase      UriBuilder uri   new UriBuilder codeBase       string path   Uri UnescapeDataString uri Path

User · Answer

I needed a universal solution that worked with a NETStandard project on any platform  iOS  Android  and Windows   To accomplish this  I decided to automatically generate a CS file via a PowerShell script  Here is the PowerShell script   param  outputFile  BuildDate cs     buildDate   Get-Date -date  Get-Date  ToUniversalTime   -Format o  class     using System  using System Globalization   namespace MyNamespace       public static class BuildDate               public const string BuildDateString      buildDate            public static readonly DateTime BuildDateUtc   DateTime Parse BuildDateString  null  DateTimeStyles AssumeUniversal   DateTimeStyles AdjustToUniversal             Set-Content -Path  outputFile -Value  class   Save the PowerScript file as GenBuildDate ps1 and add it your project  Finally  add the following line to your Pre-Build event   powershell -File   ProjectDir GenBuildDate ps1 -outputFile   ProjectDir BuildDate cs   Make sure BuildDate cs is included in your project  Works like a champ on any OS

User · Answer

If this is a windows app  you can just use the application executable path  new System IO FileInfo Application ExecutablePath  LastWriteTime ToString  yyyy MM dd

User · Answer

I am just C  newbie so maybe my answer sound silly - I display the build date from the date the executable file was last written to   string w file    MyProgram exe    string w directory   Directory GetCurrentDirectory     DateTime c3    File GetLastWriteTime System IO Path Combine w directory  w file    RTB info AppendText  Program created at      c3 ToString       I tried to use File GetCreationTime method but got weird results  the date from the command was 2012-05-29  but the date from the Window Explorer showed 2012-05-23  After searching for this discrepancy I found that the file was probably created on 2012-05-23  as shown by Windows Explorer   but copied to the current folder on 2012-05-29  as shown by File GetCreationTime command  - so to be on the safe side I am using File GetLastWriteTime command   Zalek

User · Answer

For  NET Core projects  I adapted Postlagerkarte s answer to update the assembly Copyright field with the build date   Directly Edit csproj  The following can be added directly to the first PropertyGroup in the csproj    lt Copyright gt Copyright       System DateTime   UtcNow Year  Travis Troyer     System DateTime   UtcNow ToString  s     lt  Copyright gt    Alternative  Visual Studio Project Properties  Or paste the inner expression directly into the Copyright field in the Package section of the project properties in Visual Studio   Copyright       System DateTime   UtcNow Year  Travis Troyer     System DateTime   UtcNow ToString  s       This can be a little confusing  because Visual Studio will evaluate the expression and display the current value in the window  but it will also update the project file appropriately behind the scenes   Solution-wide via Directory Build props  You can plop the  lt Copyright gt  element above into a Directory Build props file in your solution root  and have it automatically applied to all projects within the directory  assuming each project does not supply its own Copyright value    lt Project gt    lt PropertyGroup gt      lt Copyright gt Copyright       System DateTime   UtcNow Year  Travis Troyer     System DateTime   UtcNow ToString  s     lt  Copyright gt    lt  PropertyGroup gt   lt  Project gt    Directory Build props  Customize your build  Output  The example expression will give you a copyright like this   Copyright    2018 Travis Troyer  2018-05-30T14 46 23    Retrieval  You can view the copyright information from the file properties in Windows  or grab it at runtime   var version   FileVersionInfo GetVersionInfo Assembly GetEntryAssembly   Location    Console WriteLine version LegalCopyright

User · Answer

Add below to pre-build event command line   echo  date   time   gt     ProjectDir  Resources BuildDate txt    Add this file as resource  now you have  BuildDate  string in your resources   After inserting the file into the Resource  as public text file   I accessed it via  string strCompTime   Properties Resources BuildDate    To create resources  see How to create and use resources in  NET

User · Answer

You could use a project post-build event to write a text file to your target directory with the current datetime   You could then read the value at run-time   It s a little hacky  but it should work

User · Answer

One approach which I m amazed no-one has mentioned yet is to use T4 Text Templates for code generation    lt    template debug  false  hostspecific  true  language  C     gt   lt    assembly name  System Core    gt   lt    import namespace  System    gt   lt    output extension   g cs    gt  using System  namespace Foo Bar       public static partial class Constants               public static DateTime CompilationTimestampUtc   get   return new DateTime  lt   Write DateTime UtcNow Ticks ToString       gt L  DateTimeKind Utc                 Pros    Locale-independent Allows a lot more than just the time of compilation   Cons    Only applicable to libraries where you control the source Requires configuring your project  and build server  if that doesn t pick it up  to execute the template in a pre-build step   See also T4 without VS

User · Answer

it could be  Assembly execAssembly   Assembly GetExecutingAssembly    var creationTime   new FileInfo execAssembly Location  CreationTime      2019-09-08T14 29 12 2286642-04 00

User · Answer

You can use this project   https   github com dwcullop BuildInfo  It leverages T4 to automate the build date timestamp   There are several versions  different branches  including one that gives you the Git Hash of the currently checked out branch  if you re into that sort of thing   Disclosure   I wrote the module

User · Answer

In 2018 some of the above solutions do not work anymore or do not work with  NET Core   I use the following approach which is simple and works for my  NET Core 2 0 project   Add the following to your  csproj inside the PropertyGroup         lt Today gt    System DateTime   Now  lt  Today gt    This defines a PropertyFunction which you can access in your pre build command   Your pre-build looks like this  echo   today   gt    ProjectDir BuildTimeStamp txt   Set the property of the BuildTimeStamp txt to Embedded resource   Now you can read the time stamp like this  public static class BuildTimeStamp               public static string GetTimestamp                         var assembly   Assembly GetEntryAssembly                  var stream   assembly GetManifestResourceStream  NamespaceGoesHere BuildTimeStamp txt                 using  var reader   new StreamReader stream                                 return reader ReadToEnd

User · Answer

The way  As pointed out by  c00000fd in the comments  Microsoft is changing this  And while many people don t use the latest version of their compiler I suspect this change makes this approach unquestionably bad  And while it s a fun exercise I would recommend people to simply embed a build date into their binary through any other means necessary if it s important to track the build date of the binary itself   This can be done with some trivial code generation which probably is the first step in your build script already  That  and the fact that ALM Build DevOps tools help a lot with this and should be preferred to anything else   I leave the rest of this answer here for historical purposes only   The new way  I changed my mind about this  and currently use this trick to get the correct build date    region Gets the build date and time  by reading the COFF header      http   msdn microsoft com en-us library ms680313  struct  IMAGE FILE HEADER       public ushort Machine      public ushort NumberOfSections      public uint TimeDateStamp      public uint PointerToSymbolTable      public uint NumberOfSymbols      public ushort SizeOfOptionalHeader      public ushort Characteristics      static DateTime GetBuildDateTime Assembly assembly        var path   assembly GetName   CodeBase      if  File Exists path                 var buffer   new byte Math Max Marshal SizeOf typeof  IMAGE FILE HEADER    4            using  var fileStream   new FileStream path  FileMode Open  FileAccess Read                         fileStream Position   0x3C              fileStream Read buffer  0  4               fileStream Position   BitConverter ToUInt32 buffer  0      COFF header offset             fileStream Read buffer  0  4       PE 0 0              fileStream Read buffer  0  buffer Length                     var pinnedBuffer   GCHandle Alloc buffer  GCHandleType Pinned           try                       var coffHeader     IMAGE FILE HEADER Marshal PtrToStructure pinnedBuffer AddrOfPinnedObject    typeof  IMAGE FILE HEADER                 return TimeZone CurrentTimeZone ToLocalTime new DateTime 1970  1  1    new TimeSpan coffHeader TimeDateStamp   TimeSpan TicksPerSecond                      finally                       pinnedBuffer Free                        return new DateTime        endregion   The old way  Well  how do you generate build numbers  Visual Studio  or the C  compiler  actually provides automatic build and revision numbers if you change the AssemblyVersion attribute to e g  1 0    What will happen is that is that the build will be equal to the number of days since January 1  2000 local time  and for revision to be equal to the number of seconds since midnight local time  divided by 2   see Community Content  Automatic Build and Revision numbers  e g  AssemblyInfo cs   assembly  AssemblyVersion  1 0         important  use wildcard for build and revision numbers    SampleCode cs  var version   Assembly GetEntryAssembly   GetName   Version  var buildDateTime   new DateTime 2000  1  1  Add new TimeSpan  TimeSpan TicksPerDay   version Build      days since 1 January 2000 TimeSpan TicksPerSecond   2   version Revision       seconds since midnight   multiply by 2 to get original

User · Answer

For anyone that needs to get the compile time in Windows 8   Windows Phone 8       public static async Task lt DateTimeOffset  gt  RetrieveLinkerTimestamp Assembly assembly                var pkg   Windows ApplicationModel Package Current          if  null    pkg                        return null                     var assemblyFile   await pkg InstalledLocation GetFileAsync assembly ManifestModule Name           if  null    assemblyFile                        return null                     using  var stream   await assemblyFile OpenSequentialReadAsync                          using  var reader   new DataReader stream                                 const int PeHeaderOffset   60                  const int LinkerTimestampOffset   8                     read first 2048 bytes from the assembly file                  byte   b   new byte 2048                   await reader LoadAsync  uint b Length                   reader ReadBytes b                   reader DetachStream                       get the pe header offset                 int i   System BitConverter ToInt32 b  PeHeaderOffset                      read the linker timestamp from the PE header                 int secondsSince1970   System BitConverter ToInt32 b  i   LinkerTimestampOffset                    var dt   new DateTimeOffset 1970  1  1  0  0  0  DateTimeOffset Now Offset    DateTimeOffset Now Offset                  return dt AddSeconds secondsSince1970                                   For anyone that needs to get the compile time in Windows Phone 7       public static async Task lt DateTimeOffset  gt  RetrieveLinkerTimestampAsync Assembly assembly                const int PeHeaderOffset   60          const int LinkerTimestampOffset   8                      byte   b   new byte 2048            try                       var rs   Application GetResourceStream new Uri assembly ManifestModule Name  UriKind Relative                using  var s   rs Stream                                var asyncResult   s BeginRead b  0  b Length  null  null                   int bytesRead   await Task Factory FromAsync lt int gt  asyncResult  s EndRead                                   catch  System IO IOException                        return null                     int i   System BitConverter ToInt32 b  PeHeaderOffset           int secondsSince1970   System BitConverter ToInt32 b  i   LinkerTimestampOffset           var dt   new DateTimeOffset 1970  1  1  0  0  0  DateTimeOffset Now Offset    DateTimeOffset Now Offset          dt   dt AddSeconds secondsSince1970           return dt          NOTE  In all cases you re running in a sandbox  so you ll only be able to get the compile time of assemblies that you deploy with your app   i e  this won t work on anything in the GAC

User · Answer

I just do   File GetCreationTime GetType   Assembly Location

User · Answer

The above method can be tweaked for assemblies already loaded within the process by using the file s image in memory  as opposed to re-reading it from storage    using System  using System Runtime InteropServices  using Assembly   System Reflection Assembly   static class Utils       public static DateTime GetLinkerDateTime this Assembly assembly  TimeZoneInfo tzi   null                   Constants related to the Windows PE file format          const int PE HEADER OFFSET   60          const int LINKER TIMESTAMP OFFSET   8              Discover the base memory address where our assembly is loaded         var entryModule   assembly ManifestModule          var hMod   Marshal GetHINSTANCE entryModule           if  hMod    IntPtr Zero - 1  throw new Exception  Failed to get HINSTANCE                 Read the linker timestamp         var offset   Marshal ReadInt32 hMod  PE HEADER OFFSET           var secondsSince1970   Marshal ReadInt32 hMod  offset   LINKER TIMESTAMP OFFSET               Convert the timestamp to a DateTime         var epoch   new DateTime 1970  1  1  0  0  0  DateTimeKind Utc           var linkTimeUtc   epoch AddSeconds secondsSince1970           var dt   TimeZoneInfo ConvertTimeFromUtc linkTimeUtc  tzi    TimeZoneInfo Local           return dt

User · Answer

A different  PCL-friendly approach would be to use an MSBuild inline task to substitute the build time into a string that is returned by a property on the app  We are using this approach successfully in an app that has Xamarin Forms  Xamarin Android  and Xamarin iOS projects   EDIT   Simplified by moving all of the logic into the SetBuildDate targets file  and using Regex instead of simple string replace so that the file can be modified by each build without a  reset    The MSBuild inline task definition  saved in a SetBuildDate targets file local to the Xamarin Forms project for this example     lt Project xmlns  http   schemas microsoft com developer msbuild 2003  ToolsVersion  12 0  gt      lt UsingTask TaskName  SetBuildDate  TaskFactory  CodeTaskFactory       AssemblyFile    MSBuildToolsPath  Microsoft Build Tasks v12 0 dll  gt       lt ParameterGroup gt         lt FilePath ParameterType  System String  Required  true    gt       lt  ParameterGroup gt       lt Task gt         lt Code Type  Fragment  Language  cs  gt  lt   CDATA           DateTime now   DateTime UtcNow          string buildDate   now ToString  F            string replacement   string Format  BuildDate   gt     0      buildDate           string pattern     BuildDate   gt                         string content   File ReadAllText FilePath           System Text RegularExpressions Regex rgx   new System Text RegularExpressions Regex pattern           content   rgx Replace content  replacement           File WriteAllText FilePath  content           File SetLastWriteTimeUtc FilePath  now          gt  lt  Code gt       lt  Task gt     lt  UsingTask gt    lt  Project gt    Invoking the above inline task in the Xamarin Forms csproj file in target BeforeBuild      lt  -- To modify your build process  add your task inside one of the targets below and uncomment it          Other similar extension points exist  see Microsoft Common targets   -- gt     lt Import Project  SetBuildDate targets    gt     lt Target Name  BeforeBuild  gt       lt SetBuildDate FilePath    MSBuildProjectDirectory  BuildMetadata cs    gt     lt  Target gt    The FilePath property is set to a BuildMetadata cs file in the Xamarin Forms project that contains a simple class with a string property BuildDate  into which the build time will be substituted   public class BuildMetadata       public static string BuildDate   gt   This can be any arbitrary string       Add this file BuildMetadata cs to project  It will be modified by every build  but in a manner that allows repeated builds  repeated replacements   so you may include or omit it in source control as desired

User · Answer

The option not discussed here is to insert your own data into AssemblyInfo cs  the  AssemblyInformationalVersion  field seems appropriate - we have a couple of projects where we were doing something similar as a build step  however I m not entirely happy with the way that works so don t really want to reproduce what we ve got    There s an article on the subject on codeproject  http   www codeproject com KB dotnet Customizing csproj files aspx

User · Answer

Jeff Atwood had a few things to say about this issue in Determining Build Date the hard way   The most reliable method turns out to be retrieving the linker timestamp from the PE header embedded in the executable file -- some C  code  by Joe Spivey  for that from the comments to Jeff s article   public static DateTime GetLinkerTime this Assembly assembly  TimeZoneInfo target   null        var filePath   assembly Location      const int c PeHeaderOffset   60      const int c LinkerTimestampOffset   8       var buffer   new byte 2048        using  var stream   new FileStream filePath  FileMode Open  FileAccess Read           stream Read buffer  0  2048        var offset   BitConverter ToInt32 buffer  c PeHeaderOffset       var secondsSince1970   BitConverter ToInt32 buffer  offset   c LinkerTimestampOffset       var epoch   new DateTime 1970  1  1  0  0  0  DateTimeKind Utc        var linkTimeUtc   epoch AddSeconds secondsSince1970        var tz   target    TimeZoneInfo Local      var localTime   TimeZoneInfo ConvertTimeFromUtc linkTimeUtc  tz        return localTime      Usage example   var linkTimeLocal   Assembly GetExecutingAssembly   GetLinkerTime      UPDATE  The method was working for  Net Core 1 0  but stopped working after  Net Core 1 1 release gives random years in 1900-2020 range

User · Answer

Add below to pre-build event command line   echo  date   time   gt     ProjectDir  Resources BuildDate txt    Add this file as resource  now you have  BuildDate  string in your resources   To create resources  see How to create and use resources in  NET

[c#] Displaying the build date

Examples related to c#

Examples related to date

Examples related to time

Examples related to compilation