Refreshing the date of a selection process means that the publication date of your ad is updated to the day you refresh it. That is if you posted a selection process 7 days ago and today you refresh the date, your ad will now show its publication date as today's date. When you refresh the date of a selection process, it will appear again at the beginning of the job list, with the current date, obtaining more visibility.
When you unlock a selection process you can refresh the date as many times as you want, during the first 30 days since its publication.
Subscription plans do not have a 30-day limit; all jobs you create while your subscription is active can be refreshed indefinitely. Find out about all the benefits of subscription plans here.