Getting error : String was not recognized as a valid DateTime in c#

Question

Getting error like :

An unhandled exception of type 'System.FormatException' occurred in mscorlib.dll Additional information: String was not recognized as a valid DateTime.

I am using this code :

string datetime = DateTime.Parse(encrypt[1]);

or

string datetime = Convert.ToDatetime(encrypt[1]);

encrypt is a string array

In encrypt[1] I am not sure which format will come in string. i have trace some time come dd/MM/yyyy and sometime MM/dd/yyyy or MM-dd-yyyy or dd-MM-yyyy. I am not sure about format it may from above or another format come.

also use ParseExcept and TryParseExcept. but not get succeeded seems return same error

please give me proper solution.

You should know string format for parsing. Otherwise, you not be able to distinguish different dates. Example: string "01/02/2014" can be resolve to 01 Feb 2014 or 02 Jan 2014. — AndreyAkinshin
– AndreyAkinshin, Commented Nov 21, 2014 at 12:55
I am giving you my idea see: i have make one winform app and use for create key using datetime and then i had give this app to client and client said not working on decryption then i am found its datetime formate issue. so we dont know which formate will be used my client. — Jatin Gadhiya
– Jatin Gadhiya, Commented Nov 21, 2014 at 13:26
You set tag asp.net mvc. When client post data from winform app, he post it to controller or api? If so, you can try get culture info from request. Other opportunity, if you can change winform app set culture there, one for all clients. — teo van kot
– teo van kot, Commented Nov 22, 2014 at 13:10

Community · Accepted Answer · 2017-05-23 12:05:46Z

6

AndreyAkinshin already explained the real problem. I want to add this as an answer if he lets me..

Both DateTime.Parse and Convert.ToDatetime methods uses your CurrentCulture settings by default.

And your CurrentCulture can have only one of dd/MM/yyyy or MM/dd/yyyy format. It can't have both formats as a standard date and time format because it can't know which format it uses when you get a string like 01/01/2014.

None of DateTime methods can solve your problem. Even if you use DateTime.TryParseExact overload that takes formats as a string[], it parses your string with first successful format that matches in your array.

tl;dr

You have to know which format of your data has.

edited May 23, 2017 at 12:05

CommunityBot

11 silver badge

answered Nov 21, 2014 at 13:04

Soner Gönül

99.1k103 gold badges224 silver badges375 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Jatin Gadhiya Over a year ago

I am giving you my idea see: i have make one winform app and use for create key using datetime and then i had give this app to client and client said not working on decryption then i am found its datetime formate issue. so we dont know which formate will be used my client.

a-h Over a year ago

In that case, you need to adjust the code in the Winforms app to force an invariant date format. For example, force the Winforms application to use ISO 8601 date format, which is unambiguous: DateTime.Now.ToString("yyyy-MM-dd")

Patrick Hofman · Accepted Answer · 2014-11-21 12:58:54Z

1

If you don't exactly know what is coming in, you have virtually no change of getting the date format in correctly.

Take this sample:

01/02/2014

Is this the 2nd of January or the 1st of February?

If you do know the formats, you could use TryParseExact and just walk down the list until one matches:

DateTime d;
if (DateTime.TryParseExact(encrypt[1], "dd/MM/yyyy", CultureInfo.InvariantCulture, out d))
{ }
else if (DateTime.TryParseExact(encrypt[1], "yyyy/MM/dd", CultureInfo.InvariantCulture, out d))
{ }

answered Nov 21, 2014 at 12:58

Patrick Hofman

158k23 gold badges270 silver badges343 bronze badges

Comments

a-h · Accepted Answer · 2014-11-21 13:00:09Z

0

You can't tell programatically whether the date is dd/mm/yyyy or mm/dd/yyyy unless they are obviously invalid, e.g. if you're expecting dd/mm/yyyy and you get 12/14/2014, then that format can only be mm/dd/yyyy.

However, since you are receiving the data from a HTTP request (question is tagged with MVC), you can find the user's culture and use that to parse the date using, e.g.

DateTime.Parse("13/12/2014", new CultureInfo("en-GB")); // Works fine.

DateTime.Parse("13/12/2014", Thread.CurrentThread.CurrentCulture)

See http://msdn.microsoft.com/en-us/library/bb882561(v=vs.110).aspx for more information.

answered Nov 21, 2014 at 13:00

a-h

4,3042 gold badges26 silver badges30 bronze badges

Collectives™ on Stack Overflow

Getting error : String was not recognized as a valid DateTime in c#

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related