Xunit skip/ignore until a given date

IgnoreUntilFactAttribute.cs

//using System;
//using Xunit;
public class IgnoreUntilFactAttribute : FactAttribute
{
    public int Year { get; set; }
    public int Month { get; set; }
    public int Day { get; set; }

    public override string Skip
    {
        get
        {
            var skipUntil = new DateTime(Year, Month, Day);
            var shouldSkip = DateTime.Now < skipUntil;
            if (shouldSkip)
            {
                return "Skipping until " + skipUntil.ToShortDateString();
            }
            return null;
        }
    }
}