C# Online Compiler | .NET Fiddle

using System;
using System.Globalization;
					
public class Program
{
	public static void Main()
	{
		var datetime1 = new DateTime(2012, 2, 29);
		Console.WriteLine(datetime1);
		
		var datetime2 = datetime1.ToFullTaiwanDate();
		Console.WriteLine(datetime2);
		
		var datetime3 = datetime1.ToSimpleTaiwanDate();
		Console.WriteLine(datetime3);
	}
}

public static class DateTimeExtensions
{
	/// <summary>
	/// To the full taiwan date.
	/// </summary>
	/// <param name="datetime">The datetime.</param>
	/// <returns></returns>
	public static string ToFullTaiwanDate(this DateTime datetime)
	{
		TaiwanCalendar taiwanCalendar = new TaiwanCalendar();
		
		return string.Format("民國 {0} 年 {1} 月 {2} 日", 
							 taiwanCalendar.GetYear(datetime),
							 datetime.Month, 
							 datetime.Day);
	}
	
	/// <summary>
	/// To the simple taiwan date.
	/// </summary>
	/// <param name="datetime">The datetime.</param>
	/// <returns></returns>
	public static string ToSimpleTaiwanDate(this DateTime datetime)
	{
		TaiwanCalendar taiwanCalendar = new TaiwanCalendar();
		
		return string.Format("{0}/{1}/{2}",
							 taiwanCalendar.GetYear(datetime),
							 datetime.Month,
							 datetime.Day);
	}
	
}

 
using System;
using System.Globalization;
                    
public class Program
{
    public static void Main()
    {
        var datetime1 = new DateTime(2012, 2, 29);
        Console.WriteLine(datetime1);
        
        var datetime2 = datetime1.ToFullTaiwanDate();
        Console.WriteLine(datetime2);
        
        var datetime3 = datetime1.ToSimpleTaiwanDate();
        Console.WriteLine(datetime3);
    }
}
​
public static class DateTimeExtensions
{
    /// <summary>
    /// To the full taiwan date.
    /// </summary>
    /// <param name="datetime">The datetime.</param>