Setup Table Partitioning but All Data is in One Partition

This is SQl Server 2014. I configured partitioning for a new table based on a date column. But when I populated the table, all rows ( millions) went into a single partition, rather than being spread across several.
Any idea what may have gone wrong?
Thanks, Jack

what was the partition criteria?Month?Year?
can you run this query and check the output.

p.partition_number AS PartitionNumber, AS PartitionFilegroup,
p.rows AS NumberOfRows
FROM sys.partitions p
JOIN sys.destination_data_spaces dds ON p.partition_number = dds.destination_id
JOIN sys.filegroups f ON dds.data_space_id = f.data_space_id

Solved the mystery. I had to reformat the values in the partition function to match the actual columns data format. That's all it was. Thanks