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How can I resolve the stringFormat Exception error

var date= DateTime.ParseExact("16-03-2022 1:30", "dd-MM-yyyy HH:mm", CultureInfo.InvariantCulture);
When I enter 16-03-2022 13:30, it does not give an error but when the parameter is 16-03-2022 1:30, I get an error, how can I solve it?

I feel like taking a risk to answer but..
Let's go step by step. One of the good things about .NET methods is that you can see what exceptions can be thrown on that method in their documentation.
From "Exception" section on documentation it says;
FormatException
s or format is an empty string.
-or-
s does not contain a date and time that corresponds to the pattern
specified in format.
-or-
The hour component and the AM/PM designator in s do not agree.
Your s or format is not empty, your string does not have any AM or PM designator, so the only option left is "s does not contain a date and time that corresponds to the pattern specified in format." as a reason.
Also from documentation, it says;
Converts the specified string representation of a date and time to its
DateTime equivalent using the specified format and culture-specific
format information. The format of the string representation must match
the specified format exactly.
What "format" we are talking about? There are two of them. Custom date and time format strings and Standard date and time format strings. Since we are using DateTime.ParseExact, we need to consider using custom date and time format.
Let's look at all parts can be parse in your 16-03-2022 1:30 string;
16 --> Two digit day number (dd)
03 --> Two digit month number with leading zero (MM)
2022 --> Four digit year (yyyy)
1 --> One digit hour (it can be h or H because there is no time designator in your string and we can't know it's in 12-hour clock format or 24-hour clock format)
30 --> Two digit minutes (mm)
So, the proper format of your 16-03-2022 1:30 string can be either dd-MM-yyyy H:mm or dd-MM-yyyy h:mm which depends on you. If it is 24-hour format, use H specifier, if it is 12-hour format, use h specifier.

When you see the word "Exact" in ParseExact(), it means it. Any deviation from the expected format at all will cause an exception.
In this case, the HH specifier is not an exact match for the 1 value for the hour. It would match if you had 01 instead, but just 1 isn't the same thing. To match the hours without leading zeros you need a single H, creating this format string:
dd-MM-yyyy H:mm
This will still match later hours like "10" and "11". Additionally, the capital "H" instead of lower-case means it still expects 24-hour time, so numbers like "13" up to "23" still work, too.
If you could get a mix of values, that sometimes has just the 1 and sometimes might have the full 01, then you need to use a ParseExact() overload that accepts an array of formats, and provide both versions.

How to disambiguate between the 'd' Standard and Custom format strings for .Net DateTime?

In a .Net application, I would like to format a date and time in a fixed length format, but with no leading zeros for the day as below:
String.Format("{0:d MMM HH:mm:ss}", DateTime.Now);
"25 Jun 04:21:11"
This works for days of the month greater than ten, but (as documented) does not insert a leading space. Now, the following should provide the format required:
String.Format("{0,2:d}", DateTime.Now);
"25/06/2016"
but, as is seen, formats the date instead using the standard Short date format string. I can use:
String.Format("{0,2:''d} {0:MMM HH:mm:ss}", DateTime.Now.AddDays(-20));
" 5 Jun 04:21:11"
to get the desired effect, but this does not seem very satisfactory.
Is there less of a workaround to have the formatter use the Custom format string interpretation of an isolated d instead of the Short date Standard format?

To distinguish between a custom and standard format when the format is only a single character, use the % symbol. For example: {0:d} gives the standard date format, but {0:%d} gives just the day of the month. See the MSDN docs for more details.
So, you could do this:
String.Format("{0,2:%d} {0:MMM HH:mm:ss}", ...
However, consider that you could also just specify the length of the entire string:
String.Format("{0,15:d MMM HH:mm:ss}", ...
Of course, this assumes that MMM will always be three characters long. That is true for English (as .NET uses "Sep" instead of "Sept"), but isn't guaranteed for all languages and locales.
Also note that you should use HH for 24 hour time. hh gives 12 hour time, but is meaningless without using tt to indicate the meridem designation (am/pm).

convert LocalDatetime to timestamp

I have an MVC application.
At controller(from view) I am getting start date as string "Tue Jan 01 2008 00:00:00 GMT 0100 (Central Europe Standard Time)".
Could anybody please tell me how to convert this datetime to normal dd-mmy-yyyy hh:mm:ss at Controller level.
Thanks in advance....

You need to use the DateTime.ParseExact method and supply the correct format string so the code knows what each part of the input string represents.
CultureInfo provider = CultureInfo.InvariantCulture;
string format = "ddd MMM dd yyyy hh:mm tt zzz";
result = DateTime.ParseExact(dateString, format, provider);
Double check the format strings against the documentation there are several subtle and not so subtle gotchas:
"h" represents the hour in 12 hour clock
"hh" represents the hour in 12 hour clock with leading zero
"HH" represents the hour in 24 hour clock with leading zero
"m" represents a minute from 0 to 59
"M" represents a month from 1 to 12
etc.
So you may find that you think your format string is OK for the examples you have, but then a new string will come along which won't parse. You'll have to examine it to see if you've got hours in 12 or 24 hour format, etc.
Though you will have to strip of the timezone name from the end of the string first as that won't be recognised by ParseExact.

How to Parse a DateTime String to Support 24 hours timing?

I'm trying to use DateTime.TryParseExact as below:
DateTime modifiedSinceDateTime;
var succeeded = DateTime.TryParseExact(modifiedSince, "yyyy-MM-ddThh:mm:ss",
CultureInfo.InvariantCulture,
DateTimeStyles.None,
out modifiedSinceDateTime);
but it fails with this DateTime value: 2013-06-06T22:41:20 which suggests my date time pattern is not right. I think the pattern doesn't support 24 hours timing format, only up to 12 hours
What should be the correct date pattern like?

Simple enough - change the hh to HH.
hh is for 12 hour clocks, HH for 24 hours, as can be seen in the documentation for Custom Date and Time Format Strings.

Convert date c#

I have a date with the following format:
20/01/2011 7:15:28 PM
I need to convert it to something like:
2011-01-20 09:24:06
How would I do this?
Thanks in advance.

DateTime.ParseExact("20/01/2011 7:15:28 PM",
"dd/MM/yyyy h:mm:ss tt",
CultureInfo.InvariantCulture)
.ToString("yyyy-MM-dd HH:mm:ss")

The most explicit way to do this would be:
DateTime.ParseExact("20/01/2011 7:15:28 PM", "dd/MM/yyyy h:m:s tt",
CultureInfo.InvariantCulture).ToString("yyyy-MM-dd HH:mm:ss")

First you'll need to parse the original date (Assuming you don't already have it as DateTime)
Then you will need to format it, see Date formatting in c#

DateTime time = DateTime.Now; // Use current time
string format = "yyyy-MM-dd HH:mm:ss"; // Use this format
time.ToString(format); // Write to console
Formats
d
Use this to specify the numeric value for the day of the month. It will be one or two digits long.
dd
This is the same as a single d, except there are always two digits, with a leading 0 prepended if necessary.
ddd
This displays a three-letter string that indicates the current day of the week.
dddd
This displays the full string for the day of the week.
f
ff
fff
ffff
fffff
ffffff
fffffff
F
FF
FFF
FFFF
FFFFF
FFFFFF
FFFFFFF
Use the lowercase f to indicate the seconds to one digit length. Use two lowercase fs to indicate the seconds to two digits. The uppercase F patterns do the same but work differently on trailing zeros.
gg
Use this to display A.D. on your date. It is unlikely that this will be B.C. in most programs.
h
Display the hours in one digit if possible. If the hours is greater than 9, it will display two digits. Range is 1-12.
hh
Display the hours in two digits always, even if the hour is one digit. The range here will be 01-12.
H
This represents the hours in a range of 0-23, which is called military time in some parts of the world.
HH
This represents the hours in a range of 00-23. The only different here between the single H is that there is always a leading zero if the number is one digit.
K
Use this to display time zone information.
m
mm
This formats the minutes in your date format string. Here, the one m means that there is only one digit displayed if possible. The two ms means that there are always two digits displayed, with a leading zero if necessary.
M
MM
These display the months in numeric form. The one uppercase M does not have a leading zero on it. The two uppercase Ms will format a number with a leading zero if it is required.
MMM
This displays the abbreviated three-letter form of the month represented in the DateTime.
MMMM
This displays the full month string, properly capitalized.
s
ss
The lowercase s displays seconds. A single lowercase s means that you do not require a leading zero. Two lowercase s characters means you always want two digits, such as 00-59.
t
Use the lowercase t to indicate A, when the time is in the AM, and P, for when the time is in PM.
tt
Use two lowercase tts to display the full AM or PM string. You will normally want this for when you are displaying the string to a user.
y
yy
yyy
yyyy
yyyyy
These display the year to different digits. In your programs, you won't need three digits for the year, or five. Therefore, you should only consider one y, two ys, or four ys.
z
zz
zzz
These represent the offset from the UTC time on the local operating system.
:
This is the time separator.
/
This is the date separator.
Regards

Check this:
String Mydate = "20/01/2011 7:15:28 PM";
String result = DateTime.Parse(MyDate).ToString("yyyy-MM-dd HH:mm:ss")
MessageBox.Show(result);
Regards