In our java application we are trying to get the unix time from the type 1 uuid. But its not giving the correct date time values.
long time = uuid.timestamp();
time = time / 10000L; // Dividing by 10^4 as its in 100 nanoseconds precision
Calendar c = Calendar.getInstance();
c.setTimeInMillis(time);
c.getTime();
Can some one please help ?
Edit: Fixed the divisor(10^4)
From the docs for timestamp():
The resulting timestamp is measured in 100-nanosecond units since midnight, October 15, 1582 UTC.
So you need to offset it from that. For example:
Calendar uuidEpoch = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
uuidEpoch.clear();
uuidEpoch.set(1582, 9, 15, 0, 0, 0); // 9 = October
long epochMillis = uuidEpoch.getTime().getTime();
long time = (uuid.timestamp() / 10000L) + epochMillis;
// Rest of code as before
If you using datastax driver, it's:
UUIDs.unixTimestamp(uuid)
In my case, the following code worked.
final long NUM_100NS_INTERVALS_SINCE_UUID_EPOCH = 0x01b21dd213814000L;
UUID uuid = UUID.fromString("6470d760-d93d-11e9-8b32-858313a776ba");
long time = (uuid.timestamp() - NUM_100NS_INTERVALS_SINCE_UUID_EPOCH) / 10000;
// Rest of code as before
In the case someone else needs it:
long milliseconds = UuidUtil.extractUnixMilliseconds(uuid);
来源：https://stackoverflow.com/questions/13070674/get-the-unix-timestamp-from-type-1-uuid