using System;

using System.Text.RegularExpressions;

using System.Globalization;

​

class Program

{

    static void Main()

    {       

        if (DateTime.TryParseExact("26Dec 11:30pm", "d MMM h:mmtt", CultureInfo.InvariantCulture, DateTimeStyles.AllowInnerWhite, out DateTime dateTime1))

        {

        //Console.WriteLine(dateTime1);

        }

​

        if (DateTime.TryParseExact("30/12 12:00pm", "d/mm h:mmtt", CultureInfo.InvariantCulture, DateTimeStyles.AllowInnerWhite, out DateTime dateTime))

        {

            Console.WriteLine(dateTime);

        }

        //Console.WriteLine(ParseStringToDate_ByFormat("31 Dec","12:30pm", "d MMM h:mmtt"));

    }

    private static DateTime? ParseStringToDate_ByFormat(string dateStr, string timeStr, string dateTimeFormat)

    {

        var thisYear = DateTime.Now.Year.ToString();

        if (!dateStr.EndsWith(thisYear) || !dateStr.EndsWith(thisYear.Substring(2, 2)))

        {

            //dateStr += $"/{thisYear}";

        }

        timeStr = AddColonToTime(timeStr);

​

        //Console.WriteLine($"{dateStr} {timeStr}");

        if (DateTime.TryParseExact($"{dateStr} {timeStr}", dateTimeFormat, CultureInfo.InvariantCulture, DateTimeStyles.AllowInnerWhite, out DateTime dateTime))

        {

            return AddOneYearIfMoreThan6MonthsOld(dateTime);

        }

​

        return null;

    }

     private static string AddColonToTime(string timeStr)

 {

     string pattern = @"^(\d{1,2})(\d{2})?(am|pm)?$";

​

     // Use Regex.Replace to format the string

     return Regex.Replace(timeStr.ToLower().Replace(" ", "").Replace(".", ""), pattern, match =>

     {

         string hour = match.Groups[1].Value;       // Capture the hour part

         string minute = match.Groups[2].Success ? match.Groups[2].Value : "00"; // Default to "00" if no minute part

         string period = match.Groups[3].Value;    // Capture "am" or "pm" if present

​

         return $"{hour}:{minute}{period}";

     });

 }

​

 private static DateTime AddOneYearIfMoreThan6MonthsOld(DateTime dt)

 {

     // If less than today by 6 months

     if (dt <= DateTime.Now.AddMonths(-6))

     {

        return dt.AddYears(1);

     }

     // If more than today by 6 months

     if (dt > DateTime.Now.AddMonths(6))

     {

         return dt.AddYears(-1);

     }

​

     return dt;

 }

​

    static string ExtractNumericValue(string input)

    {

        // Use regular expression to extract digits

        Match match = Regex.Match(input, @"\d+");

        return match.Success ? match.Value : string.Empty;

    }

}

​