Rails. How to store time of day (for schedule)?

I made an app recently that had to tackle this problem. I decided to store open_at and closed_at in seconds from midnight in a simple business hour model. ActiveSupport includes this handy helper for finding out the time in seconds since midnight:

Time.now.seconds_since_midnight

This way I can do a simple query to find out if a venue is open:

BusinessHour.where("open_at > ? and close_at < ?", Time.now.seconds_since_midnight, Time.now.seconds_since_midnight)

Any tips for making this better would be appreciated =)