using System;

public class Hello{
	public static string GetIntervalTime(string datetime)
	{
		DateTime t = DateTime.Parse(datetime);
		var now = TimeZoneInfo.ConvertTime(DateTime.Now, TimeZoneInfo.Utc);
		var seconds = Math.Round((now - t).TotalSeconds);

		var months = Math.Round(seconds / (30 * 60 * 60 * 24));
		if (months > 0)
		{
			return months.ToString() + "月前";
		}
		var days = Math.Round(seconds / (60 * 60 * 24));
		if (days > 0)
		{
			return days.ToString() + "日前";
		}
		var hours = Math.Round(seconds / (60 * 60));
		if (hours > 0)
		{
			return hours.ToString() + "時間前";
		}
		var minutes = Math.Round(seconds / 60);
		if (minutes > 0)
		{
			return minutes.ToString() + "分前";
		}

		return seconds.ToString() + "前";
	}

	public static void Main(){
		System.Console.WriteLine(DateTime.Now);
		System.Console.WriteLine(GetIntervalTime("2017-1-28T14:55:46"));
		System.Console.WriteLine(GetIntervalTime("2017-2-25T23:00:00"));
	}
}