gistfile1.cs

            Transform("NOTHING", () =>
            {
                return null as string;
            });

            Transform(@"(TODAY|TOMORROW|YESTERDAY) at ([0-9]{2})([0-9]{2})\Z", (string day, string time1, string time2) =>
            {
                var datePart = string.Empty;
                switch (day)
                {
                    case "TODAY":
                        datePart = DateTime.UtcNow.Date.ToShortDateString();
                        break;
                    case "TOMORROW":
                        datePart = DateTime.UtcNow.Date.AddDays(1).ToShortDateString();
                        break;
                    case "YESTERDAY":
                        datePart = DateTime.UtcNow.Date.AddDays(-1).ToShortDateString();
                        break;
                }
                var timePart = time1 + ":" + time2;
                var returnVal = DateTime.SpecifyKind(DateTime.Parse(string.Format("{0} {1}:00", datePart, timePart)), DateTimeKind.Utc);

                return returnVal;
            });

            Transform(@"(TODAY|TOMORROW|YESTERDAY)\Z", day =>
            {
                switch (day)
                {
                    case "TODAY":
                        return DateTime.UtcNow.Date;
                    case "TOMORROW":
                        return DateTime.UtcNow.Date.AddDays(1);
                    default:
                        return DateTime.UtcNow.Date.AddDays(-1);
                }
            });
            Patients();
        }