Welcome to Calvert County's Calendar of Events. Welcome visitor. Click for free membership!  Already a member? Click here to Login. To use this free service you must register. This service is available only to companies with physical locations in Calvert County, Maryland. Once you are a registered user, you are able to add, edit, renew or remove your event listings. Your listing is valid for 30 days. If you have not filled the position within that time, you may renew the listing for another 30 days. You will receive an e-mail notifying you that your listing will expire.