Oh...gotcha. I thought we were talking about a mint state/proof coin lacking a date. The way Rueben puts it I'd tend to say that a coin that lacks a date is worth whatever denomination is stamped onto it, nothing more.
Distinct difference between 1800 to 1807(Draped Bust) and 1808 to 1814(Classic Heads). Pictures will help us determine if we can date it.
In some cases it can be possible to determine the die variety and therefor the date. For most coins it will not matter that much as the value will be minimal, but if the coin turns out to be a rare date of variety then the coin can have significant value. For example my 1799 S-188 is a dateless coin. Now it would be worth a lot more with a date, but even dateless it is probably worth at least a couple hundred dollars. (AG starts around $1200) I found an dateless 1804 in a group that a collector brought me awhile back, that's also a couple hundred. I'd pay $1000 for a dateless 1801 S-217 or 1796 S-96