If the numbers are Long Integers like 37014, your data is OK -- merely the wrong format. Often data from Excel is treated either as a Double or Text -- Access doesn't always get dates right.
Try going into Design view in the table. Check the data type. If it's Number, change it to Date and save the table. You may want to define a Format in the bottom section before saving. If Access lets you save the table you should be set.
Denis