Move instances of `Time.parse` into a Utils method

Use a centralized `Utils.parse_date` method to do all of the date parsing (except in one case where a special `rescue` is used). Also, add error messages where they didn't exist already.
It would be awesome to always have the `input` string printed, so the user can search (ack/ag) for that string to quickly find & change it. What do you think?