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How to convert this UTC datetime string to DateTime object c#

I have been trying to convert this string to a DateTime object in C#
2019-09-23T08:34:00UTC+1
I've tried using DateTime.Parse but it is throwing an exception for
"String was not recognized as a valid DateTime."

I'm sorry but you seem like a victim of garbage in, garbage out.
That's an unusual format, that's why before I suggest a solution for you, first thing I want to say is "Fix your input first if you can".
Let's say you can't fix your input, then you need to consider a few things;
First of all, if your string has some parts like UTC and/or GMT, there is no custom date and time format specifier to parse them. That's why you need to escape them as a string literal. See this question for more details.
Second, your +1 part looks like a UTC Offset value. The "z" custom format specifier is what you need for parse it but be careful, this format specifier is not recommended for use with DateTime values since it doesn't reflect the value of an instance's Kind property.
As a solution for DateTime, you can parse it like I would suggest;
var s = "2019-09-23T08:34:00UTC+1";
DateTime dt;
if(DateTime.TryParseExact(s, "yyyy-MM-dd'T'HH:mm:ss'UTC'z", CultureInfo.InvariantCulture,
DateTimeStyles.AdjustToUniversal, out dt))
{
Console.WriteLine(dt);
}
which gives you 2019-09-23 07:34:00 as a DateTime and which has Utc as a Kind property.
As a solution for DateTimeOffset - since your string has a UTC Offset value you should consider to parse with this rather than Datetime
-, as Matt commented, you can use it's .DateTime property to get it's data like;
var s = "2019-09-23T08:34:00UTC+1";
DateTimeOffset dto;
if(DateTimeOffset.TryParseExact(s, "yyyy-MM-dd'T'HH:mm:ss'UTC'z", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dto))
{
Console.WriteLine(dto.DateTime);
}
which gives you the same result DateTime but Unspecified as a .Kind property.
But, again, I strongly suggest you to fix your input first.

Use TryParseExact to convert the string to datetime. Here is the sample code to covert the given format(s) to datetime
private static DateTime ParseDate(string providedDate) {
DateTime validDate;
string[] formats = {
"yyyy-MM-ddTHH:mm:ss"
};
var dateFormatIsValid = DateTime.TryParseExact(
providedDate, formats, CultureInfo.InvariantCulture, DateTimeStyles.None, out validDate);
return dateFormatIsValid ? validDate: DateTime.MinValue;
}
Then, use this function to convert the string. I am replacing UTC+1 to empty string
static void Main(string[] args) {
string strdatetime = "2019-09-23T08:34:00UTC+1";
DateTime dateTime = ParseDate(strdatetime.Replace("UTC+1", ""));
Console.WriteLine(dateTime);
}

How to parse a timespan in order to add it to a datetime?

I've got a string in the following format: 05/06/2019|1330|60
The output I'm looking for is: 05/06/2019T14:30:00
I'm attempting to parse out the TimeSpan portion right now:
public static string getProcedureEndingDateTime (string input) {
//05/06/2019|1330|60
string myDate = input.Split ( '|' ) [0];
DateTime myDateTime = DateTime.Parse (myDate);
string myTime = input.Split('|')[1];
string hours = myTime.Substring(0,2);
string minutes = myTime.Substring(2,2);
TimeSpan myTimeSpan = TimeSpan.Parse($"{hours}:{minutes}");
myDateTime.Add(myTimeSpan);
return myDateTime.ToString();
}
But right now, getting the following output:
To get the above output I'm calling my function like so:
Console.WriteLine (getProcedureEndingDateTime("05/06/2019|1330|60"));
How do I parse the string "1330" into a TimeSpan?

No need to us a Timespan here, just call ParseExact instead with a proper format to do it in one line.
var myDateTime = DateTime.ParseExact("05/06/2019|1330|60", "dd/MM/yyyy|HHmm|60", CultureInfo.InvariantCulture);
Console.WriteLine(myDateTime.ToString());
//this gives 2019-06-05 1:30:00 PM, format depends on your PC's locale
I don't know what the 60 part is, you can adjust the format or substring it out beforehand.

The problem is because Add() returns a new DateTime instance, which means you're currently discarding it. Store it, and return that from your function instead, like so:
var adjusted = myDateTime.Add(myTimeSpan);
return adjusted.ToString();

Try using the numeric values as exactly that, numbers.
Also, the other issue with your code is the DateTime.Add() method doesn't add to that DateTime variable. Instead it returns a new variable, which you are ignoring.
Try this:
public static string getProcedureEndingDateTime (string input) {
string[] parts = input.Split('|');
string myDate = parts[0];
DateTime myDateTime = DateTime.Parse (myDate);
string myTime = parts[1];
if (!int.TryParse(myTime.Substring(0,2), out int hours))
hours = 0;
if (!int.TryParse(myTime.Substring(2,2), out int minutes))
minutes = 0;
TimeSpan myTimeSpan = new TimeSpan(hours, minutes, 0);
myDateTime += myTimeSpan;
return myDateTime.ToString();
}

Assuming the date shown is May 6th (and not June 5th), and also assuming the 60 represents a time zone offset expressed in minutes west of GMT, and also assuming you want the corresponding UTC value, then:
public static string getProcedureEndingDateTime (string input) {
// example input: "05/06/2019|1330|60"
// separate the offset from the rest of the string
string dateTimeString = input.Substring(0, 15);
string offsetString = input.Substring(16);
// parse the DateTime as given, and parse the offset separately, inverting the sign
DateTime dt = DateTime.ParseExact(dateTimeString, "MM/dd/yyyy|HHmm", CultureInfo.InvariantCulture);
TimeSpan offset = TimeSpan.FromMinutes(-int.Parse(offsetString));
// create a DateTimeOffset from these two components
DateTimeOffset dto = new DateTimeOffset(dt, offset);
// Convert to UTC and return a string in the desired format
DateTime utcDateTime = dto.UtcDateTime;
return utcDateTime.ToString("MM/dd/yyyy'T'HH:mm:ss", CultureInfo.InvariantCulture);
}
A few additional points:
Not only is the input format strange, but so is your desired output format. It is strange to see a T separating the date and time and also see the date in the 05/06/2019 format. T almost always means to use ISO 8601, which requires year-month-day ordering and hyphen separators. I'd suggest either dropping the T if you want a locale-specific format, or keep the T and use the standard format. Don't do both.
In ISO 8601, it's also a good idea to append a Z to UTC-based values. For DateTime values, the K specifier should be used for that. In other words, you probably want the last line above to be:
return utcDateTime.ToString("yyyy-MM-dd'T'HH:mm:ssK", CultureInfo.InvariantCulture);
// outputs: "2019-05-06T14:30:00Z"
You might want to not format a string here, but instead return the DateTime or DateTimeOffset value. It's usually better to create a string only at the time of display.
Don't forget that the DateTime struct is immutable. In your question you were ignoring the return value of the Add method.

Convert 12 hour time to Timespan C#

Using ASP.NET Forms, I'm encountering a problem with converting a 12 hour time into a timespan. Below I'm combining DateTime with TimeSpan as the user chooses a date and then a time. The fields are controlled by javascript.
DateTime DateResult = DateTime.TryParse(txtDate.Text, out DateResult) ? DateResult : DateTime.Today;
TimeSpan TimeResult = TimeSpan.TryParseExact(txtTime.Text, "h:mm tt", CultureInfo.InvariantCulture, out TimeResult) ? TimeResult : new TimeSpan();
DateResult = DateResult.Add(TimeResult)
So parsing the date works fine, but Timespan doesn't. One example:
Date Entered: 08/03/2018
Time Entered: 3:00 AM
Values are gettined passed okay but time fails so DateResult becomes "08/03/2018 00:00" but not "08/03/2018 03:00". I have also tried using the method TimeSpan.TryParse but no luck with that one.
I've also made sure that the format is correct by manually entering the time in the database behind the scenes. The gridview has a column that shows the full date in this format "dd/MM/yyyy h:mm tt", and works.
Anyone please share some light? Ideally, I would like to avoid any third party plug-ins.

Parse them together
Simplest thing is to just concatenate the strings before parsing as a single DateTime, e.g.
var dateEntered = #"08/03/2018";
var timeEntered = #"3:00 am";
DateTime result;
var completeDateString = dateEntered + " " + timeEntered;
var ok = DateTime.TryParse(completeDateString, out result);
if (!ok) result = DateTime.Today;
Console.WriteLine(result);
Output:
8/3/2018 3:00:00 AM
Ta da
If you have to parse them separately
If you'd like to work with the fields separately, you still can (I guess you'd have to do this if you want the time format to be exact but the date portion to be flexible, as it is in your example). But TimeSpan.TryParseExact is really different from DateTime.Parse. The format codes are different; it doesn't support the ":" character (except as a literal with an escape, e.g. "\:"), for example, or the "tt" formatting specifier. I'm guessing the concept of am/pm has to do with an absolute point in time, not a relative time offset, so isn't provided for. But you can still parse the textbox as a DateTime and use its time portion.
You can probably shorten this a bit but this example gives you everything you need:
static public DateTime ParseDateTime(string input)
{
DateTime output;
var ok = DateTime.TryParse(input, out output);
if (ok) return output;
return DateTime.Today;
}
static public TimeSpan ParseTime(string input)
{
DateTime output;
var ok = DateTime.TryParseExact(input, #"h:mm tt", CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.NoCurrentDateDefault, out output);
return output.Subtract(output.Date);
}
public static void Main()
{
var dateEntered = #"08/03/2018";
var timeEntered = #"3:00 am";
DateTime dateResult = ParseDateTime(dateEntered);
TimeSpan timeResult = ParseTime(timeEntered);
DateTime finalResult = dateResult.Add(timeResult);
Console.WriteLine(finalResult);
}
Output:
8/3/2018 3:00:00 AM
Code on DotNetFiddle

See ParseExact or https://msdn.microsoft.com/en-us/library/system.timespan.tryparseexact(v=vs.110).aspx for TryParseExact should work for both DateTime as well as TimeSpan inter alia
Fyi it's called the meridian and see also AM/PM to TimeSpan

How to convert informal string value to Date time in c#

All of my friend.
I want to convert informal string to dateTime in c#. Here my string value is "01042016".How can convert? can i need another step to change DateTime.
This is my code:
string FinancialYear = "01042016-31032017";
string[] splitDate = FinancialYear.Split('-');
DateTime startDate = Convert.ToDateTime(splitDate[0].ToString(),"dd/MM/yyyy"));

As we can see that the input date will be in the format ddMMyyyy so here the best option for converting the input to DateTime object is DateTime.TryParseExact the code for this will be :
string FinancialYear = "01042016-31032017";
string[] splitDate = FinancialYear.Split('-');
DateTime startDate ;
if(DateTime.TryParseExact(splitDate[0],"ddMMyyyy",CultureInfo.InvariantCulture,DateTimeStyles.None,out startDate))
{
// Proceed with the startDate it will have the required date
}
else
// Show failure message

This will create an Enumerable where index 0 is the first date and index 1 is the second date.
string FinancialYear = "01042016-31032017";
var dateRange = FinancialYear.Split('-')
.Select(d => DateTime.ParseExact(d, "ddMMyyyy", CultureInfo.InvariantCulture);

If you are not sure of the format your best bet is using DateTime.Parse() or DateTime.TryParse()
You are not 100% guaranteed that the date will be parsed correctly, especially in cases where the day and month numbers could be in the wrong order.
It is best to specify a required date format if you can so you can be sure the date was parsed correctly.

if you string is in static format, you can convert it by reconvert it to valid string format first such as
string validstring = splitDate[0].ToString().Substring(4,4)+"-"+splitDate[0].ToString().Substring(2,2) +"-"+ splitDate[0].ToString().Substring(0,2);
DateTime startDate = Convert.ToDateTime(validstring,"dd/MM/yyyy"));

how to convert time in string format into date time format using C#

i have textbox that accepts time format like this 12:40 PM but would like to convert it into time format like this 12:40:00 basically without the PM or AM. Here is what i have so far:
string StartTime = ((TextBox)TestDV.FindControl("txtBST")).Text.ToString();
thanks

One option would be to parse into a DateTime and then back to a string:
string s = "12:40 PM";
DateTime dt = DateTime.Parse(s);
string s2 = dt.ToString("HH:mm:ss"); // 12:40:00
Be aware, however, that most operations work better with a DateTime versus a string representation of a DateTime.

First you should parse it to a DateTime, then format it. It sounds like your input format is something like hh:mm tt and your output format is HH:mm:ss. So, you'd have:
string input = "12:40 PM"
DateTime dateTime = DateTime.ParseExact(input, "hh:mm tt",
CultureInfo.InvariantCulture);
string output = dateTime.ToString("HH:mm:ss", CultureInfo.InvariantCulture);
Note that:
I've used DateTime.ParseExact which will throw an exception if the parsing fails; you may want to use DateTime.TryParseExact (it depends on your situation)
I've used the invariant culture for both operations here. I don't know whether or not that's correct for your scenario.
I've used hh:mm, but you might want h:mm... would you expect "1 PM" or "01 PM"?
You don't parse seconds, so that part will always be 0... is that okay?

Since you are bringing it in as a string this is actually kind of easy.
string StartTime = ((TextBox)TestDV.FindControl("txtBST")).Text.ToString();
DateTime dt = new DateTime();
try { dt = Convert.ToDateTime(StartTime); }
catch(FormatException) { dt = Convert.ToDateTime("12:00 AM"); }
StartTime = dt.ToString("HH:mm");
So you bring in your string, and convert it to a date. if the input is not a valid date, this will default it to 00:00. Either way, it gives you a string and a DateTime object to work with depending on what else you need to do. Both represent the same value, but the string will be in 24-Hour format.
Cheers!!