Hive from_unixtime for milliseconds

timestamp_ms is unixtime in milliseconds

SELECT from_unixtime(floor(CAST(timestamp_ms AS BIGINT)/1000), 'yyyy-MM-dd HH:mm:ss.SSS') as created_timestamp FROM table_name;

Solved it by following query:

select timestamp, from_unixtime(CAST(timestamp/1000 as BIGINT), 'yyyy-MM-dd') from Hadoop_V1_Main_text_archieved limit 10;

The type should be double to ensure precision is not lost:

select from_unixtime(cast(1601256179170 as double)/1000.0, "yyyy-MM-dd hh:mm:ss.SSS") as event_timestamp