SELECT
pr.value,
$PARTITION.[pfAVMX_HISTORY_YEAR](CAST(pr.value AS DATE)) as PartitionID
from sys.partition_functions pf
join sys.partition_range_values pr
on pr.function_id = pf.function_id
where pf.name = 'pfAVMX_HISTORY_YEAR'
--and pr.value = cast('20000101' as DATE)