using System;

using System.Text.RegularExpressions;

using System.Globalization;

​

string intervalString = "02:30:00 PM";

string format = "hh\\:mm\\:ss tt"; // Assuming 12-hour format with colons and am/pm

​

// Use a consistent culture like CultureInfo.InvariantCulture

CultureInfo culture = CultureInfo.InvariantCulture;

​

// Validate the format specifier

if (!string.IsNullOrEmpty(intervalString) && !string.IsNullOrEmpty(format))

{

    if (TimeSpan.TryParseExact(intervalString, format, culture, out TimeSpan interval))

    {

        Console.WriteLine("'{0}' ({1}) --> {2}", intervalString, format, interval);

    }

    else

    {

        Console.WriteLine("Unable to parse '{0}' using format {1}", intervalString, format);

    }

}

else

{

    Console.WriteLine("Invalid time string or format provided.");

}

​