Set AccountExpires on Account Enable

Hi Team,

So we are a certain account type creation process where for security reasons, the account is disabled automatically post creation. Typically, the account is enabled straight away, but it could be a day or two later. 

Is there a way that when we enable the account that I could get it to set the AccountExpires value with today's date + 31. Assume this would be a workflow? 

Thanks in advance