Adding Multiple Dates to MySQL database

We have a Joomla website, which adds dates to a diary. We have code written to add a date to a database, but we would like our customers to be able to add multiple dates at a time. We need someone who can write an SQL Query to add multiple dates to a database. The code that we already have is written in PHP. See the attached file below, I have created a .jpg file of what I would like the form to look like. We already have the individual date and description working and saving, so the multiple dates section is what we want added. Note that this information will be used to check our clients availability, and they will need to be able to delete individual dates, if they want later. The form on the attached picture below is set as a popup box, but an individual page can be created if necessary.