Read Exif DateTimeOriginal and SubSecTimeOriginal of JPG file and convert its centiseconds in Base36. This is intended for JPG files by Nikon camera.

ExifDate.cs

using System.Globalization;
using System.Text;

internal static class ExifDate
{
    public static string? GetBase36UnixCentiseconds(string filePath)
    {
        if (TryRead(filePath, out DateTimeOffset dateTime, out int subSecTime))
        {
            var centiseconds = dateTime.ToUnixTimeSeconds() * 100 + subSecTime; // in centiseconds
            Console.WriteLine(centiseconds);
            return Convert(centiseconds);
        }
        return null;

        static string Convert(long value)
        {
            const string array = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

            if (value == 0)
                return "0";

            var buffer = new StringBuilder();
            while (value > 0)
            {
                buffer.Insert(0, array[(int)(value % 36)]);
                value /= 36;
            }
            return buffer.ToString();
        }
    }

    public static bool TryRead(string filePath, out DateTimeOffset dateTime, out int subSecTime)
    {
        dateTime = default;
        subSecTime = 0;

        if (!File.Exists(filePath))
            return false;

        using var image = System.Drawing.Image.FromFile(filePath);

        string? GetValue(int id)
        {
            try
            {
                var prop = image.GetPropertyItem(id);
                if (prop?.Value is null)
                    return null;

                return Encoding.ASCII.GetString(prop.Value).TrimEnd('\0');
            }
            catch (ArgumentException)
            {
                return null;
            }
        }

        var dateTimeOriginal = GetValue(36867);
        if (!DateTimeOffset.TryParseExact(dateTimeOriginal, "yyyy:MM:dd HH:mm:ss", null, DateTimeStyles.None, out dateTime))
            return false;

        var subSecTimeOriginal = GetValue(37521);
        if (!int.TryParse(subSecTimeOriginal, out subSecTime) || (subSecTime >= 100))
            return false;

        return true;
    }
}

Program.cs

internal class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Get & convert Exif date");

        foreach (var filePath in Directory.GetFiles(args[0], "*.JPG", SearchOption.AllDirectories))
        {
            var converted = ExifDate.GetBase36UnixCentiseconds(filePath);
            Console.WriteLine($"{filePath} -> {converted}");
        }
    }
}