Date multiple format conversion in .net framework

January 27, 2023

I need to convert below 2 string formats to DateTime

"M/dd/yyyy hh:mm:ss tt", "MM-dd-yyyy hh:mm"

     //  CultureInfo enUS = new CultureInfo("en-IN");
        CultureInfo enUS = new CultureInfo("en-GB");
i)          dt = "07/30/2022 5:30:39 PM";
ii)        // dt = "7/30/2022 5:30:39 PM";
iii)       // var dt = "11-07-2022 09:22";

        DateTime dateValue;
    
        string[] formatStrings = { "M/dd/yyyy hh:mm:ss tt", "MM/dd/yyyy hh:mm:ss tt", "MM-dd-yyyy hh:mm" };
        if (DateTime.TryParseExact(dt, formatStrings, enUS, DateTimeStyles.None, out dateValue))
            return dateValue;

The above code convert only ‘-‘ date fornat not ‘/’ format .
Is it possible to convert to ‘/’ date format

EXPECTED OUTPUT:  30/07/2022  for i & ii
                  07/11/2022  for iii

>Solution :

The input you have is:

"07/30/2022 5:30:39 PM"

The pattern you’re trying to match that against is:

"M/dd/yyyy hh:mm:ss tt"

Note that your input has two digits for the month, but you’ve told it not to match a leading zero; and that you hour doesn’t start with a leading zero but your pattern says it should.

Your pattern should be this:

"MM/dd/yyyy h:mm:ss tt"

If you try that you’ll see it works.

Here is working code for all of your inputs:

CultureInfo enUS = new("en-US");

string[] dts =
{
    "07/30/2022 5:30:39 PM",
    "7/30/2022 5:30:39 PM",
    "11-07-2022 09:22",
};

string[] formatStrings =
{
    "MM/dd/yyyy h:mm:ss tt",
    "M/dd/yyyy h:mm:ss tt",
    "MM-dd-yyyy hh:mm"
};

IEnumerable<string> results =
    from dt in dts
    let x = DateTime.TryParseExact(dt, formatStrings, enUS, DateTimeStyles.None, out DateTime dateValue) ? (DateTime?)dateValue : null
    where x != null
    select x.Value.ToString("dd/MM/yyy");

It produces: