Parse string to DateTime in C

Question

I have date and time in a string formatted like that one    2011-03-21 13 26    year-month-day hour minute   How can I parse it to System DateTime   I want to use functions like DateTime Parse   or DateTime ParseExact   if possible  to be able to specify the format of the date manually

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You can also use XmlConvert ToDateString  var dateStr    2011-03-21 13 26   var parsedDate   XmlConvert ToDateTime dateStr   yyyy-MM-dd hh mm      It is good to specify the date kind  the code is   var anotherParsedDate   DateTime ParseExact dateStr   yyyy-MM-dd hh mm   CultureInfo InvariantCulture  DateTimeStyles AssumeUniversal     More details on different parsing options http   amir-shenodua blogspot ie 2017 06 datetime-parsing-in-net html

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Put the value of a human-readable string into a  NET DateTime with code like this   DateTime ParseExact  April 16  2011 4 27 pm    MMMM d  yyyy h mm tt   null

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The simple and straightforward answer --   using System   namespace DemoApp App    public class TestClassDate       public static DateTime GetDate string string date                DateTime dateValue          if  DateTime TryParse string date  out dateValue               Console WriteLine  Converted   0   to  1     string date  dateValue           else             Console WriteLine  Unable to convert   0   to a date    string date           return dateValue            public static void Main                 string inString    05 01 2009 06 32 00           GetDate inString                     Output     Converted  05 01 2009 06 32 00  to 5 1 2009 6 32 00 AM

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DateTime Parse   should work fine for that string format  Reference   http   msdn microsoft com en-us library 1k1skd40 aspx Y1240  Is it throwing a FormatException for you

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Try the following code   Month   Date   DateTime Now Month ToString       Year   DateTime Now Year ToString     ViewBag Today   System Globalization CultureInfo InvariantCulture DateTimeFormat GetMonthName Int32 Parse Month     Year

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As I am explaining later  I would always favor the TryParse and TryParseExact methods  Because they are a bit bulky to use  I have written an extension method which makes parsing much easier  var    dtStr    quot 2011-03-21 13 26 quot   DateTime  dt   dtStr ToDate  quot yyyy-MM-dd HH mm quot     Or more simply  if you want to use the date patterns of your current culture implicitly  you can use it like   DateTime  dt   dtStr ToDate     In that case no specific pattern need to be specified  Unlike Parse  ParseExact etc  it does not throw an exception  and allows you to check via if  dt HasValue       continue processing   else      do error handling   whether the conversion was successful  in this case dt has a value you can access via dt Value  or not  in this case  it is null   That even allows to use elegant shortcuts like the  quot Elvis quot -operator     for example  int  year   dtStr  ToDate  quot yyyy-MM-dd HH mm quot    Year   Here you can also use year HasValue to check if the conversion succeeded  and if it did not succeed then year will contain null  otherwise the year portion of the date  There is no exception thrown if the conversion failed   Solution     The       ToDate        extension method Try it in  NetFiddle public static class Extensions            lt summary gt          Extension method parsing a date string to a DateTime   lt para  gt           lt  summary gt           lt param name  quot dateTimeStr quot  gt The date string to parse lt  param gt           lt param name  quot dateFmt quot  gt dateFmt is optional and allows to pass          a parsing pattern array or one or more patterns passed          as string parameters lt  param gt           lt returns gt Parsed DateTime or null lt  returns gt      public static DateTime  ToDate this string dateTimeStr  params string   dateFmt                 example  var dt    quot 2011-03-21 13 26 quot  ToDate new string    quot yyyy-MM-dd HH mm quot                                                               quot M d yyyy h mm ss tt quot              or simpler            var dt    quot 2011-03-21 13 26 quot  ToDate  quot yyyy-MM-dd HH mm quot    quot M d yyyy h mm ss tt quot          const DateTimeStyles style   DateTimeStyles AllowWhiteSpaces        if  dateFmt    null                  var dateInfo   System Threading Thread CurrentThread CurrentCulture DateTimeFormat          dateFmt dateInfo GetAllDateTimePatterns                  var result   DateTime TryParseExact dateTimeStr  dateFmt  CultureInfo InvariantCulture                     style  out var dt    dt   null as DateTime         return result            Some information about the code You might wonder  why I have used InvariantCulture calling TryParseExact  This is to force the function to treat format patterns always the same way  otherwise for example  quot   quot  could be interpreted as decimal separator in English while it is a group separator or a date separator in German   Recall we have already queried the culture based format strings a few lines before so that is okay here  Update   ToDate    without parameters  now defaults to all common date time patterns of the thread s current culture   Note that we need the result and dt together  because TryParseExact does not allow to use DateTime   which we intend to return  In C  Version 7 you could simplify the ToDate function a bit as follows      in C 7 only   quot DateTime dt  quot  - no longer required  declare implicitly  if  DateTime TryParseExact dateTimeStr  dateFmt       CultureInfo InvariantCulture  style  out var dt   result   dt   or  if you like it even shorter      in C 7 only  Declaration of result as a  quot one-liner quot   -   var result   DateTime TryParseExact dateTimeStr  dateFmt  CultureInfo InvariantCulture                style  out var dt    dt   null as DateTime    in which case you don t need the two declarations DateTime  result   null  and DateTime dt  at all - you can do it in one line of code   It would also be allowed to write out DateTime dt instead of out var dt if you prefer that   The old style of C  would have required it the following way  I removed that from the code above        DateTime  result   null       DateTime dt       if  DateTime TryParseExact dateTimeStr  dateFmt          CultureInfo InvariantCulture  style  out dt   result   dt   I have simplified the code further by using the params keyword  Now you don t need the 2nd overloaded method any more   Example of usage var dtStr  quot 2011-03-21 13 26 quot       var dt dtStr ToDate  quot yyyy-MM-dd HH mm quot    if  dt HasValue        Console WriteLine  quot Successful  quot               dt Value now contains the converted DateTime       else       Console WriteLine  quot Invalid date format  quot       As you can see  this example just queries dt HasValue to see if the conversion was successful or not  As an extra bonus  TryParseExact allows to specify strict DateTimeStyles so you know exactly whether a proper date time string has been passed or not   More Examples of usage The overloaded function allows you to pass an array of valid formats used for parsing converting dates as shown here as well  TryParseExact directly supports this   e g  string   dateFmt     quot M d yyyy h mm ss tt quot    quot M d yyyy h mm tt quot                          quot MM dd yyyy hh mm ss quot    quot M d yyyy h mm ss quot                          quot M d yyyy hh mm tt quot    quot M d yyyy hh tt quot                          quot M d yyyy h mm quot    quot M d yyyy h mm quot                          quot MM dd yyyy hh mm quot    quot M dd yyyy hh mm quot    var dtStr  quot 5 1 2009 6 32 PM quot    var dt dtStr ToDate dateFmt    If you have only a few template patterns  you can also write  var dateStr    quot 2011-03-21 13 26 quot   var dt   dateStr ToDate  quot yyyy-MM-dd HH mm quot    quot M d yyyy h mm ss tt quot      Advanced examples  You can use the    operator to default to a fail-safe format  e g  var dtStr    quot 2017-12-30 11 37 00 quot   var dt    dtStr ToDate       dtStr ToDate  quot yyyy-MM-dd HH mm ss quot     In this case  the  ToDate   would use common local culture date formats  and if all these failed  it would try to use the ISO standard format  quot yyyy-MM-dd HH mm ss quot  as a fallback  This way  the extension function allows to  quot chain quot  different fallback formats easily  You can even use the extension in LINQ  try this out  it s in the  NetFiddle above   var strDateArray   new      quot 15-01-2019 quot    quot 15 01 2021 quot     var patterns new      quot dd-MM-yyyy quot    quot dd MM yyyy quot     var dtRange   strDateArray Select s   gt  s ToDate patterns    dtRange Dump      which will convert the dates in the array on the fly by using the patterns and dump them to the console   Some background about TryParseExact Finally  Here are some comments about the background  i e  the reason why I have written it this way   I am preferring TryParseExact in this extension method  because you avoid exception handling - you can read in Eric Lippert s article about exceptions why you should use TryParse rather than Parse  I quote him about that topic 2   This  unfortunate design decision1    annotation  to let the Parse method throw an exception   was so vexing that of course the frameworks team implemented TryParse shortly thereafter  which does the right thing   It does  but TryParse and TryParseExact both are still a lot less than comfortable to use  They force you to use an uninitialized variable as an out parameter which must not be nullable and while you re converting you need to evaluate the boolean return value - either you have to use an ifstatement immediately or you have to store the return value in an additional boolean variable so you re able to do the check later  And you can t just use the target variable without knowing if the conversion was successful or not  In most cases you just want to know whether the conversion was successful or not  and of course the value if it was successful   so a nullable target variable which keeps all the information would be desirable and much more elegant - because the entire information is just stored in one place  That is consistent and easy to use  and much less error-prone  The extension method I have written does exactly that  it also shows you what kind of code you would have to write every time if you re not going to use it   I believe the benefit of  ToDate strDateFormat  is that it looks simple and clean - as simple as the original DateTime Parse was supposed to be - but with the ability to check if the conversion was successful  and without throwing exceptions   1  What is meant here is that exception handling  i e  a try         catch Exception ex          block  - which is necessary when you re using Parse because it will throw an exception if an invalid string is parsed - is not only unnecessary in this case but also annoying  and complicating your code  TryParse avoids all this as the code sample I ve provided is showing   2  Eric Lippert is a famous StackOverflow fellow and was working at Microsoft as principal developer on the C  compiler team for a couple of years

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var dateStr     2011-03-21 13 26   var dateTime   DateTime ParseExact dateStr   yyyy-MM-dd HH mm   CultureInfo CurrentCulture     Check out this link for other format strings

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DateTime Parse   will try figure out the format of the given date  and it usually does a good job  If you can guarantee dates will always be in a given format then you can use ParseExact     string s    2011-03-21 13 26    DateTime dt        DateTime ParseExact s   yyyy-MM-dd HH mm   CultureInfo InvariantCulture      But note that it is usually safer to use one of the TryParse methods in case a date is not in the expected format   Make sure to check  Custom Date and Time Format Strings when constructing format string  especially pay attention to number of letters and case  i e   MM  and  mm  mean very different things    Another useful resource for C  format strings is String Formatting in C

[c#] Parse string to DateTime in C#

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