Codeignitor Date formatting Check (prior to submission)

I need to allow the user to submit a date and time mm/dd/yyyy hh:mm on a form.  I would like to not use javascript to validate the entry is valid, prior to submitting to the database.

I know about the date validation in CI; however, I do not see anything for date and time together.  Does anyone have a good example of using a standard input box, taking the submission to the controller, validating that the data is a valid date and time and then submitting to the database?  

Any help would be greatly appreciated.  I have a function that converts the date to the approriate strings for mktime in PHP, but maybe I need to check via a regular expression?  Thoughts?  Suggestions?  Examples?  All greatly appreciated.