Convert date time to file date time

Question

Hi,
I have standard delphi function which conver datetime to filedatetime here is the description
function DateTimeToFileDate(DateTime: TDateTime): Integer;
Description
Use DateTimeToFileDate to convert a TDateTime value, which is the representation of date-and-time values used by the VCL, to a DOS date-and-time value.
For example, use DateTimeToFileDate to convert a TDateTime value to a
format that can be used as the Age parameter of FileSetDate. You may
also need to use DateTimeToFileDate to convert a TDateTime so that it
is compatible with the Time field of the TSearchRec record used by the FindFirst
and FindNext functions.
Lo returns the low-order Byte of the argument X as an unsigned value. X is an expression of type Integer.
Use Hi to obtain the high-order byte of an expression of type Word or Integer.
Note:     Hi treats Integer as a 16-bit value, even if it is 32-bit.
This is the delphi code that convert the date
year=2003
month=5
day=28
sec=57
min=45
hr=13
msec=107
LongRec(Result).Lo := (Sec shr 1) or (Min shl 5) or (Hour shl 11);
LongRec(Result).Hi := Day or (Month shl 5) or ((Year - 1980) shl 9);
output Result is --> 784100796
Any help will be highly appreciated.
Thanks.

Answer 1

You use the java.util.GregorianCalendar to extract month, day, etc from a date.
Then you use the shift operator ('<<') to construct the number.