Cloning an activity will create a new listing for the activity and will duplicate all the details of the activity.
This should be used if you want to save time and add a similar activity that you already have listed but some of the details are different eg the venue or price.
You should not clone an activity if you are just looking to add more dates to an activity that you already have listed on the site. In this case, please refer to the How do I add more dates and times for my activity?
Tip: When you duplicate an activity, it's important to change the name of the new activity so that you can tell the difference between the two activities.