discarding milliseconds from the average time calculated

Here is my code:

SELECT cluster_id, AVG(min_per_imei_cluster::TIME) as avg_time 
FROM arrival
group by cluster_id

The avg_time column gives values with milliseconds and beyond. How do I truncate or round to the nearest second?

I tried using

AVG(min_per_imei_cluster::TIME)::timestamp(0)

but got the following error:

SQL Error [42846]: ERROR: cannot cast type interval to timestamp without time zone

>Solution :

It looks like you can use the date_trunc function to specify the level of precision that you want. So in this instance, you would do date_trunc(‘second’,min_per_imei_cluster).

I hope this helps!