function ParseDateTimeStamp(
    const DateString: string
): TIdDateTime;

TIdDateTime - native date/time parsed from the string.

ParseDateTimeStamp is a procedure used to parse a native date/time value from the string specified in DateString. DateString is expected in one of the following formats: 

ParseDateTimeStamp examines the value in DateString to determine if time values are present and should be included in the return value. 

ParseDateTimeStamp encodes the year, month, day, and optional time components into the native date/time in the return value.