Converting Double to DateTime?

Question

I have a .CSV file which I am reading into a C# program. In one of the columns, there is a date, but it is in the \"general\" format, so it shows up in the .CSV as a number.

Answer 1

In case you are looking for FromOADate in .Net Core it is not there.

I dissembled the implementation .Net Framework and created an extension method.

        public static DateTime FromOADate(this double date)
        {
            return new DateTime(DoubleDateToTicks(date), DateTimeKind.Unspecified);
        }

        internal static long DoubleDateToTicks(double value)
        {
            if (value >= 2958466.0 || value <= -657435.0)
                throw new ArgumentException("Not a valid value");
            long num1 = (long)(value * 86400000.0 + (value >= 0.0 ? 0.5 : -0.5));
            if (num1 < 0L)
                num1 -= num1 % 86400000L * 2L;
            long num2 = num1 + 59926435200000L;
            if (num2 < 0L || num2 >= 315537897600000L)
                throw new ArgumentException("Not a valid value");
            return num2 * 10000L;
        }

Still need to test it.