How to convert a milliseconds date to a DateTime?

Question

I have this time from an server: 1475245457452 The Date and Time for this is: 30.9.2016, 16:24:17

How can I convert this 1475245457452 in Delphi to a correct Date and Time?

I re-tagged your question taking a guess at your version. There is no XE10. My guess is Berlin, but it won't make a difference either way. — David Heffernan, Sep 30 '16 at 14:41
I corrected the header to read *milli*seconds instead of *micro*seconds, as the value you provided is indeed milliseconds (from Unix epoch). — Tom Brunberg, Sep 30 '16 at 16:06

David Heffernan · Accepted Answer · 2016-09-30T16:00:47.697

You did not say, but I can guess that this quantity is actually milliseconds, measured from the Unix epoch. So convert them using UnixToDateTime from the System.DateUtils unit:

{$APPTYPE CONSOLE}

uses
  System.SysUtils,
  System.DateUtils;

begin
  Writeln(DateTimeToStr(UnixToDateTime(1475245457452 div 1000)));
end.

I have divided by 1000 to convert into seconds because UnixToDateTime expects the time in seconds rather than milliseconds. If you wish to retain the millisecond part of the time then you can readily increment the date time value by the remainder of the division.

It is important to stress that time is always measured in some unit system, and relative to some origin, or epoch. It's never enough to know just a value, but you have to know both the units and the epoch. Yes, it is often easy enough to guess these, but it would usually be better to read the specification of the software producing the time value to find out definitively what the value is.

@Pascal if this is the correct solution, please mark the answer as correct — Gregor Brandt, Oct 04 '16 at 17:29

How to convert a milliseconds date to a DateTime?

1 Answers1