Delete files older than 3 months old in a directory using .NET

Question

I would like to know (using C#) how I can delete files in a certain directory older than 3 months, but I guess the date period could be flexible.

Just to be clear:

Answer 1

For example: To go My folder project on source, i need to up two folder. I make this algorim to 2 days week and into four hour

public static void LimpiarArchivosViejos()
    {
        DayOfWeek today = DateTime.Today.DayOfWeek;
        int hora = DateTime.Now.Hour;
        if(today == DayOfWeek.Monday || today == DayOfWeek.Tuesday && hora < 12 && hora > 8)
        {
            CleanPdfOlds();
            CleanExcelsOlds();
        }

    }
    private static void CleanPdfOlds(){
        string[] files = Directory.GetFiles("../../Users/Maxi/Source/Repos/13-12-2017_config_pdfListados/ApplicaAccWeb/Uploads/Reports");
        foreach (string file in files)
        {
            FileInfo fi = new FileInfo(file);
            if (fi.CreationTime < DateTime.Now.AddDays(-7))
                fi.Delete();
        }
    }
    private static void CleanExcelsOlds()
    {
        string[] files2 = Directory.GetFiles("../../Users/Maxi/Source/Repos/13-12-2017_config_pdfListados/ApplicaAccWeb/Uploads/Excels");
        foreach (string file in files2)
        {
            FileInfo fi = new FileInfo(file);
            if (fi.CreationTime < DateTime.Now.AddDays(-7))
                fi.Delete();
        }
    }