DateTime parsing problem (DateTime.ParseExact) - c#

[Please vote to close this - see my last comment.]
Hi,
Something like this:
DateTime.ParseExact("25/12/2008 00:00:00", "dd/MM/yyyy HH:mm:ss", CultureInfo.InvariantCulture);
works fine on my development machine but not after deployment (server).
I guess it has to do with some time zone configuration. I have tried:
<%# ... UICulture="en" Culture="en-US" %>
with no avail. Any suggestions on a postcard please. Thanks.
Christian
PS: Exception:
String was not recognized as a valid DateTime
PPS: I have updated the question. I actually feed in the time bit. sorry about that!
PPPS:
I have now realised that all this has to do with Excel and oledb. The string 25/12/2008 looks like this "12/25/2008 12:00:00 AM" on the server and like this "25/12/2008 00:00:00" on the developement machine. I adjusted the time zone of the server to UK without avail. What else can I do? Thank and sorry about all this confusion!!!

Something like this
You'd do better posting exactly what failed, and the exact error, rather than "something like" what failed.
I would expect your sample to give a FormatException, since the string you're converting ("25/12/2008", no time) does not match the format specified ("dd/MM/yyyy hh:mm:ss").
Also a bit strange to be using hh rather than HH in your format - hh is a 12-hour clock.
I would expect any of the following to work.
// No time component
DateTime.ParseExact("25/12/2008", "dd/MM/yyyy", new CultureInfo("en-US"));
// Works for hours <=12, result is always AM
DateTime.ParseExact("25/12/2008 11:00:00", "dd/MM/yyyy hh:mm:ss", new CultureInfo("en-US"));
// Works for hours using 24-hour clock
DateTime.ParseExact("25/12/2008 13:00:00", "dd/MM/yyyy HH:mm:ss", new CultureInfo("en-US"));

When parsing a string to DateTime, always consider that the date could have one or two digits for day and month. For example, it could be MM/dd/yyyy or M/d/yyyy or MM/d/yyyy or M/dd/yyyy. If you use ParseExact and you don't consider that, you'll get an exception. Try this:
DateTime date = DateTime.ParseExact(
dateText, // date in string
new string[] { "M/d/yyyy", "MM/dd/yyyy", "M/dd/yyyy", "MM/d/yyyy" }, // formats (you can add more)
CultureInfo.InvariantCulture,
DateTimeStyles.None);

try
DateTime.ParseExact("25/12/2008", "dd/MM/yyyy hh:mm:ss", CultureInfo.InvariantCulture);

Related

Parsing string into Datetime

This may sound really dumb but I'm struggling with some String parsing into some DateTime
This should be pretty easy with DateTime.ParseExact but the thing is I'm not even able to tell what the pattern is.
string[] patterns = new string[] {"dd/MM/yyyy", "ddMMyyyy", "dd/MM/yyyy HH:mm:ss"};
DateTime test = DateTime.ParseExact(DatMEC, patterns, CultureInfo.InvariantCulture,DateTimeStyles.None);
I used to convert my String to DateTime that way, but in a few cases, I'm facing some parsing error.
I logged the String to check the format, and here is what I've got causing the exception :
String dateException="2/1/2004 12:00:00 AM"
I was wondering what was the appropriate pattern for this?
I tried the following :
"dd/MM/yyyy HH:mm:ss aaa"
"d/M/yyyy HH:mm:ss a"
"M/d/yyyy HH:mm:ss a"
"MM/dd/yyyy HH:mm:ss aaa"
But none of them seems to work.
Am I missing something? I even wonder if it's parseable?
You need to use single day and month numbers d and M and use hh specifier instead of HH since it's 12-hour clock time. Also tt specifier for AM designator.
d/M/yyyy hh:mm:ss tt
Further reading:
Custom Date and Time Format Strings

ParseExact inverse my day and month

my code below throw an exception as invalid date time. the error occur after i publish it to my server. working find at my developing PC
string str = "27-07-2015 6:15 pm";
DateTime dt = Convert.ToDateTime(DateTime.ParseExact(str, "dd-MM-yyyy h:mm tt", null).ToString("dd-MM-yyyy hh:mm tt"));
it takes '27' as month and '7' as day.
what i did to solve the problem:
i already update the datetime format on that server to dd-MM-yyyy
i double checked the capital and small letter of the date time format.
change the 'null' to 'CultureInfo.InvariantCulture'
change 'pm' to 'PM', 'tt' to 'TT'
read through all the resources i could find on google and stackoverflow, nothing's help.
am i missing something here? i know i did... :(
As #Rawling correctly noted, you're parsing the datetime twice: first, using your custom formatting, and second, using the system's default formatting.
This is silly - you already have the DateTime from the ParseExact method:
string str = "27-07-2015 6:15 pm";
var dt = DateTime.ParseExact(str, "dd-MM-yyyy h:mm tt", null);
That's it, you're done. No need to convert to string again, and parse that once more (and even worse, using the same custom formatting to do the ToString, so the subsequent Convert.ToDateTime is bound to fail anywhere that's not the default datetime formatting).
There are a few possibilities;
Let's analyze your DateTime.ParseExact(str, "dd-MM-yyyy h:mm tt", null) part first. This will be parsed your 27-07-2015 6:15 pm string successfully if;
Your CurrentCulture's TimeSeparator is : and
Your CurrentCulture's PMDesignator is PM (not empty string)
If both are okey, you have successfully parsed a DateTime.
After that, you generate it's textual representation with dd-MM-yyyy hh:mm tt format. And that's still depends on your CurrentCulture, your result might have PM or not. For both case, there is no guaranteed to parse your string with Convert.ToDateTime method because it will be parsed your string only if it is a standard date and time format of your CurrentCulture.
On the other side, what you do doesn't make sense to me. You parse your string first, then you generate string representation of it, then you try to parse this string again. Doesn't make sense, right?
I strongly suspect you just need;
string str = "27-07-2015 6:15 pm";
DateTime dt = DateTime.ParseExact(str, "dd-MM-yyyy h:mm tt", CultureInfo.InvariantCulture);

Can not Parse string to DateTime in Windows Phone 7

I am trying to convert the string to DateTime. But I can not convert.
DateTime dt = DateTime.Parse("16/11/2014", CultureInfo.InvariantCulture);
Console.WriteLine("Date==> " + dt);
The error is FormatException.
My input time format is "dd/MM/yyyy".
Please let me any idea to resolve my problem.
Given that you know your input format, you should specify it with `ParseExact:
DateTime dt = DateTime.ParseExact(text, "dd/MM/yyyy",
CultureInfo.InvariantCulture);
I would always recommend being as explicit as you can be about date/time formats. It makes your intention very clear, and avoids the possibility of getting months and days the wrong way round.
As Soner has stated, CultureInfo.InvariantCulture uses MM/dd/yyyy as its short date pattern, as you can validate with:
Console.WriteLine(CultureInfo.InvariantCulture.DateTimeFormat.ShortDatePattern)
As a mild plug, you might want to consider using my Noda Time project for your date/time handling - aside from anything else, that allows you to treat a date as a date, rather than as a date and time...
Because InvariantCulture doesn't have dd/MM/yyyy as a standard date and time format, but it has MM/dd/yyyy as a standard date and time format.
That's why it thinks your string is MM/dd/yyyy format, but since there is no 16 as a month in Gregorian calender, you get FormatException.
Instead of that, you can use DateTime.TryParseExact method to specify exact format like;
string s = "16/11/2014";
DateTime dt;
if(DateTime.TryParseExact(s, "dd/MM/yyyy", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
}

How to parse a string into a date time format in C#

i have a string which contains date time this...
string S="08/18/2013 24:00:00"
DateTime DT = DateTime.ParseExact(S, "MM/dd/yyyy HH:mm:ss", null);
i want to parse it into date time but shows an exception like this.
The DateTime represented by the string is not supported in calendar System.Globalization.GregorianCalendar.
please tell me any solution for this problem.
The problem is with the hour being 24. DateTime doesn't support this, as far as I'm aware.
Options:
Use my Noda Time project which does support 24:00:00, but basically handles it by adding a day (it doesn't preserve a difference between that and "end of previous day")
Keep using DateTime, manually replace "24:00:00" with "00:00:00" when it occurs, and remember to add a day afterwards
If you want to preserve the information that it was actually "end of the day" you'd need to do that separately, and keep the information alongside the DateTime / LocalDateTime.
You should also parse with the invariant culture as other answers have suggested - you're not trying to parse a culture-specific string; you know the exact separators etc.
string S="08/18/2013 00:00:00"; // here is the first problem occurred
DateTime DT = DateTime.ParseExact(S, "MM/dd/yyyy hh:mm:ss", System.Globalization.CultureInfo.InvariantCulture);
From The "HH" Custom Format Specifier
The "HH" custom format specifier (plus any number of additional "H"
specifiers) represents the hour as a number from 00 through 23; that
is, the hour is represented by a zero-based 24-hour clock that counts
the hours since midnight.
So, using 24 as an hour is invalid on this case.
Try with hh format with 00 instead like;
string S = "08/18/2013 00:00:00";
DateTime DT = DateTime.ParseExact(S, "MM/dd/yyyy hh:mm:ss", CultureInfo.InvariantCulture);
Here a DEMO.
If you really want to use 24:00:00 as a hour, take a look Noda Time which developed by Jon.

Unable to parse date time in C#

I know such questions are in ton here. Please go through once
I have a string coming from textbox having current date e.g. 10/9/2012, my class property is of DateTime? type. I am using Convert.ToDateTime(datetime_string_from_textbox) but it gives me a FormatException. I then tried DateTime.ParseExact(string, format, CultureInfo, DateTimeStyle) as suggested by Jon Skeet here but still it gave me the same exception.
One more thing — my local machine date time format is dd-mm-yyyy. When I switch this to mm/dd/yyyy format the code works fine. So basically , I want to know how to parse a valid datetime string to a DateTime object irrespective of the regional settings, or any settings or any dependency on local machine.
Is this possible?
Update : Code in use
employee.JoiningDate = DateTime.ParseExact(string.Format("{0} 00:00:00", JoiningDate.Text.Trim()), "MM/dd/yyyy hh:mm:ss", CultureInfo.InvariantCulture, DateTimeStyles.AdjustToUniversal | DateTimeStyles.AssumeUniversal);
Existing Problem and Required Solution
My system datetime shows 24-10-2012 (that is, 24th Oct) and I have 10/17/2012 in my text box (that is, 17th Oct) since the text box date is also valid and after deployment again the client datetime format will become unknown so, I want a generic way to parse any valid datetime string irrespective of regional settings. Is this possible?
This should work:
var date = DateTime.ParseExact(str, "M/d/yyyy", CultureInfo.InvariantCulture);
As tested bellow: 
Try formatting your date to international date format using this method:
How would you format DateTime in international format?
Also you can check this for your current culture:
Set Default DateTime Format c#
It totally depends on the machine settings. DateTime.ParseExact(str, "dd/MM/yyyy", CultureInfo.InvariantCulture); will work for British format but it will give format exception on US format. So use format according to your machine settings.
Try the following if it works
var formatInfo = new DateTimeFormatInfo();
formatInfo.ShortDatePattern = "MM/dd/yyyy";
DateTime.Parse(date, formatInfo);

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