Hi There! This is definitely possible! You can create an automated workflow using our super cool Automation feature. You can create a new workflow based on a specific group or all contacts in your audience when they sign-up using a sign-up form to send a campaign after a specified timeframe. See the screenshot below of an example:
Check out our Resource Center here for more details on Automation. Feel free to give me a shout here with any questions or if there is anything else I can do to help. Happy Automating!