Adds String#valid_date? and String#valid_time? methods to add utility to the Rails String#to_date and String#to_time methods. Determines whether the string contains a valid date or time, to check before converting to a date and avoiding an exception.

Examples:

"2008-01-01".valid_date?          #=> true
"20080101".valid_date?            #=> true
"0000-00-00".valid_date?          #=> false
"".valid_date?                    #=> nil

"2008-01-01".valid_time?          #=> true
"20080101".valid_time?            #=> true
"2008-01-01 12:00".valid_time     #=> true
"2008-01-01 52:99".valid_time     #=> false
"0000-00-00".valid_time?          #=> false
"".valid_time?                    #=> nil

This gem is released under a broad open-source license. See LICENSE for more details.