How do you represent MS-DTYP `DATETIME` in Java 8 Instant?

Question

In the Microsoft Spec, DATETIME is represented as 2 32-bit integers: low and high

Reference: https://docs.microsoft.com/en-us/open

Answer 1

Ah I was barking up the wrong tree when I split the bytes in half like that.

Basically it's just saying that the units are in 100ns.

And the Epoch has a different base time too. So you have to add the offset as well.

So it is:

    private static final long DATETIME_EPOCH_DIFF_1601;
    static {
        LocalDateTime time32Epoch1601 = LocalDateTime.of(1601, Month.JANUARY, 1, 0, 0);
        Instant instant = time32Epoch1601.atZone(ZoneOffset.UTC).toInstant();
        DATETIME_EPOCH_DIFF_1601 = (instant.toEpochMilli() - Instant.EPOCH.toEpochMilli()) / 1000;
    }
    Instant answer = Instant.ofEpochSecond(fullval / 10000000 + DATETIME_EPOCH_DIFF_1601)