Contains the desired value of the TElX509Certificate.ValidFrom property.
Use this property to specify the date from which the certificate must be valid.
The date and time are stored and retrieved in Universal Coordinate Time (UTC).
[Pascal] The date is represented in DATE (OLE_DATE) format, which is double that contains the number of days since 30 Dec 1899 in it's integer part and time of day in milliseconds in fractional part.
[.NET] The date is represented as System.DateTime structure