Extract giving wrong week of year

All,

I’m seeing some odd behavior from the extract function.
Any idea why extract would think January 3rd of next year is the 53rd week
of the year?

Thanks

Ben

[bprimrose(at)primrose partitioning]$ psql

Null display is "¤".

Line style is unicode.

Output format is wrapped.

Timing is on.

psql (9.3.9)

Type "help" for help.

bprimrose(at)home=> select extract (week from '2016-01-03
00:01:00'::timestamp);

date_part

───────────

53

(1 row)

Time: 1.128 ms

bprimrose(at)home=> select version();

version

─────────────────────────────────────────────────────────────────────────────────────────────────────────────

PostgreSQL 9.3.9 on x86_64-redhat-linux-gnu, compiled by gcc (GCC) 4.9.2
20150212 (Red Hat 4.9.2-6), 64-bit

(1 row)