Develop Reference

Convert date and time into Correct format to compare to current date

I have a date in this format "2017-03-29" and time like "09:30", How do I conver toDatetime.
Following is how I have
string date = "2017-03-29";
string time = "09:30"
I need to convert this to DateTime in c#.
I also need to compare this converted DateTime with current dateTime, I will be using this in comparison in Linq

Use DateTime.ParseExact. Also your problem statement and code shown have nothing to do with Linq. The code below assumes the hours are in 24 hour format, adjust accordingly if that is not the case and provide an am/pm flag.
string date = "2017-03-29";
string time = "09:30";
var dateTime = DateTime.ParseExact(date+time, "yyyy-MM-ddHH:mm", null);

I would say the same as #Sam, but I don't have enough reputation to comment.
string date = "2017-03-29";
string time = "09:30";
string dateTimeString = string.Format("{0} {1}", date, time);
DateTime dateTime = DateTime.ParseExact(dateTimeString, "yyyy-MM-dd HH:mm", CultureInfo.InvariantCulture);
Note that the Kind of the resulting DateTime is DateTimeKind.Unspecified. Convert it as necessary.

Using the variables provided:
string dateTime = date + " " + time;
DateTime d = Convert.ToDateTime(dateTime);

Converting an inputted string into a date

I have been trying to get a date conversion to wrok to convert from a string to a date I have looked at msdn and some other stack o questions but multiple ways have not worked. I am making a console app and it needs a valid date to check other dates. below is my current attempt.
string StartDate, EndDate;
Console.WriteLine("Input Start date");
StartDate = Console.ReadLine();
StartDate = DateTime.Parse(StartDate);
I currently set the variable StartDate and then set it a value depending on what the user enters and then it should change this to a date using the Parse

you are trying to assign the DateTime value to string StartDate, which is wrong. So change it like below:
string StartDate, EndDate;
DateTime date;
Console.WriteLine("Input Start date");
StartDate = Console.ReadLine();
date = DateTime.Parse(StartDate);

A string is not a DateTime and a DateTime not a String. So you might be able to parse a string to a date but you cannot use the string variable for the DateTime and vice-versa. You need two variables:
string startDateInput = Console.ReadLine();
DateTime startDate = DateTime.Parse( startDateInput );
Since this could fail if the input string is not a valid date you should use TryParse:
DateTime startDate;
bool validDate = DateTime.TryParse(startDateInput, out startDate);
if(validDate)
Console.Write("Valid date: " + startDate.ToLongDateString());

Try using Convert.ToDateTime();
Example:
string date = "01/08/2008";
DateTime dt = Convert.ToDateTime(date);

Use DateTime.TryParse()
Converts the specified string representation of a date and time to its
DateTime equivalent and returns a value that indicates whether the
conversion succeeded.
DateTime date;
if (!DateTime.TryParse("DateString", out date))
{
MessageBox.Show("Invalid string!");
}

You need to specify the Date Format.
Try This: Example format MM-dd-yyyy
Console.WriteLine("Input Start date Format -> MM-dd-yyyy");
string StartDate = Console.ReadLine();
DateTime YourDate = DateTime.ParseExact(StartDate,"MM-dd-yyyy",
System.Globalization.CultureInfo.InvariantCulture);

string to MM/dd/yyyy

I have a string like this:
3/4/2013 or like this 11/10/2012. This is in mm/dd/yyyy format which I want to convert to MM/dd/yyy. I am doing like this:
DateTime publicationDate = DateTime.ParseExact(myDate, "MM/dd/yyyy", CultureInfo.InvariantCulture);
This is throwing me an error:
String was not recognized as a valid DateTime.
What is going on here?
EDIT:
After reviewing all the answers, I want to show Month and Day of the DateTime variable.
So I cannot do something like this:
string publicationDate = DateTime.ParseExact(myDate, "M/d/yyyy", CultureInfo.InvariantCulture).ToString("MM/dd/yyyy");
Having a string will not solve my problem because I am using this variable to show only day and month.
When I tried parsing this 'publicationDate' back to DateTime is truncates the '0's from month and day.
Hope I made my point here.
Answered:
string publicationDate = DateTime.ParseExact(myDate, "M/d/yyyy", CultureInfo.InvariantCulture).ToString("MM/dd");

You should add leading zeroes to the month and day.
This way: 04/03/2013
var myDateTime = DateTime.ParseExact(
"03/04/2013",
"MM/dd/yyyy",
System.Globalization.CultureInfo.InvariantCulture);
If leading zeroes are a problem, then do:
var myDateTime = DateTime.ParseExact(
"3/4/2013",
"M/d/yyyy",
System.Globalization.CultureInfo.InvariantCulture);
Finally, if you want to add leading zeroes:
string myFormattedDateTime = DateTime.ParseExact(
"3/4/2013",
"M/d/yyyy",
System.Globalization.CultureInfo.InvariantCulture)
.ToString("MM/dd/yyyy");

Use this pattern instead: "M/d/yyyy" to parse it and "MM/dd/yyyy" for ToString:
DateTime publicationDate = DateTime.ParseExact(dt, "M/d/yyyy", CultureInfo.InvariantCulture);
// if you want to display two digits for day and month:
Console.WriteLine(publicationDate.ToString("MM/dd/yyyy"));
It works for both as you can see here: http://ideone.com/M7luBD

Simple solution was this:
string publicationDate = DateTime.ParseExact(myDate, "M/d/yyyy", CultureInfo.InvariantCulture).ToString("MM/dd");
Thank you all for your answers!

Convert your string ToDateTime first. Make sure you have leading zeroes.
string date = "03/04/2013";
DateTime dt = Convert.ToDateTime(date);

[TestCase("3/4/2013", 3, 4, 2013)]
[TestCase("11/4/2013", 11, 4, 2013)]
public void DateTest(string date, int month, int day, int year)
{
var publicationDate = DateTime.ParseExact(date, "M/d/yyyy", CultureInfo.InvariantCulture);
Assert.AreEqual(day, publicationDate.Day);
Assert.AreEqual(month, publicationDate.Month);
Assert.AreEqual(year, publicationDate.Year);
}
Both test cases pass.
If your format asks for MM/dd/yyyy then you need to supply the string as such (04/03/2013 instead of 4/3/2013). So either
use M/d/yyyy if your supplied date is without leading zero's
or use the MM/dd/yyyy if you can supply leading zero's

Can any one tell what's wrong in my conversion from string to Date time

I write the following code to convert a string to Date time but i am getting an exception so can any one help me
string str = "2/30/2011";
DateTime dt = DateTime.ParseExact(str, "yyMMdd", CultureInfo.InvariantCulture);`

Other than the non-existing date? February 30th is not a date unless you're using MySQL...
Oh, and of course, your format is wrong. It should be M/dd//yyyy (because that's how your string is formatted).

try
DateTime dt = DateTime.ParseExact(str, "MM/dd/yyyy", CultureInfo.InvariantCulture);

You have to do it like this:
string str = "2/30/2011";
DateTime dt = DateTime.ParseExact(str, "M/dd/yyyy", CultureInfo.InvariantCulture);`

Morover, you're using a format yyMMdd whereas your date is expressed in M/dd/yy

Parse C# string to DateTime

I have a string like this:
250920111414
I want to create a DateTime object from that string. As of now, I use substring and do it like this:
string date = 250920111414;
int year = Convert.ToInt32(date.Substring(4, 4));
int month = Convert.ToInt32(date.Substring(2, 2));
...
DateTime dt = new DateTime(year, month, day ...);
Is it possible to use string format, to do the same, without substring?

Absolutely. Guessing the format from your string, you can use ParseExact
string format = "ddMMyyyyHHmm";
DateTime dt = DateTime.ParseExact(value, format, CultureInfo.InvariantCulture);
or TryParseExact:
DateTime dt;
bool success = DateTime.TryParseExact(value, format,
CultureInfo.InvariantCulture, DateTimeStyles.None, out dt);
The latter call will simply return false on parse failure, instead of throwing an exception - if you may have bad data which shouldn't cause the overall task to fail (e.g. it's user input, and you just want to prompt them) then this is a better call to use.
EDIT: For more details about the format string details, see "Custom Date and Time Format Strings" in MSDN.

You could use:
DateTime dt = DateTime.ParseExact(
date,
"ddMMyyyyHHmm",
CultureInfo.InvariantCulture);

string iDate = "05/05/2005";
DateTime oDate = Convert.ToDateTime(iDate);
DateTime oDate = DateTime.ParseExact(iString, "yyyy-MM-dd HH:mm tt",null);
DateTime Formats