jQuery validation plugin won't validate date

[bluemonkey69]

I am using the plugin with success with all my form fields except the date. I can input any number and it will validate as true. Here is the rule I'm using:

registration_date: {
required: true,
date: true
}

I notice that on the plugin site, the same is true. Am I overlooking something?

Thanks!

[DanInMa]

you may want to list a link to the plugin you are using.