I wouldn't edit Chronic. Chronic's only function is to parse natural language date time, not other input. You might be interested in the Nickel
gem here:
https://github.com/iainbeeston/nickel
This separates time from other language.
n = Nickel.parse("use the force on july 1st at 9am", Time.now)
n.message #=> "use the force"
n.occurrences.first.start_date #=> "20110701"