For a specific recommendation, I've used the str2time function from Date::Parse module. It parses a myriad of commonly used formats including "YYYY-MM-DD" and "YYYY/MM/DD".

When parsing dates of the form mm/dd/yyyy, it might be of interest to you to know that different countries can interpret such a date differently. In the US, for instance, the date 03/04/05 will be interpreted as March 4th, (20)05. In Europe, however, it can be interpreted as April 3rd, (20)05.