Parsing data to convert to types is always going to be a minefield.

Take this simple example.

var dateString = "2/1/2025";
var date = DateTime.Parse(dateString);
Console.WriteLine(date.ToString("d MMM yyyy"));

This parses the string “2/1/2025” into a DateTime.

This prints the following:

2 Jan 2025

It happens to print this because my machine is set to the locale en-KE, where the short date format is day/month/year.

If I change my locale, either in my system settings or in code, I get very different results:

Thread.CurrentThread.CurrentCulture = new CultureInfo("en-gb");
var dateString = "2/1/2025";
var date = DateTime.Parse(dateString);
Console.WriteLine(date.ToString("d MMM yyyy"));

Here I am changing the locale to en-US, where the short date format is month/day/year

This prints the following:

1 Feb 2025

A completely different result!

Give you cannot control the user’s settings, you have to tell the runtime what to do in all situations.

For this, we use the ParseExact method.

var dateString = "2/1/2025";
if (DateTime.TryParseExact(dateString, ParseFormat, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTime date))
{
  Console.WriteLine(date.ToString("d MMM yyyy"));
}
else
{
  Console.WriteLine($"Could not parse {dateString} in the format {ParseFormat}");
}

Here, I am using TryParseExact rather than the direct ParseExact because I want to inform the user when parsing fails.

We have discussed TryParse before.

Now, the locale does not matter - we always get the same result:

string[] cultures = ["en-US", "en-GB", "fr-FR", "es-ES"];
foreach (var culture in cultures)
{
  Thread.CurrentThread.CurrentCulture = new CultureInfo(culture);
  const string ParseFormat = "d/M/yyyy";
  var dateString = "2/1/2025";
  if (DateTime.TryParseExact(dateString, ParseFormat, CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTime date))
  {
    Console.WriteLine($"{culture} - {date:d MMM yyyy}");
  }
  else
  {
    Console.WriteLine($"Could not parse {dateString} in the format {ParseFormat}");
  }
}

This code prints the following:

en-US - 2 Jan 2025
en-GB - 2 Jan 2025
fr-FR - 2 janv. 2025
es-ES - 2 ene 2025

Here we can see that regardless of the culture, we always get back January 2, 2025.

TLDR

Prefer TryParseExact and ParseExact over TryParse and Parse

The code is in my GitHub.

Happy hacking!