I vote for a single column to keep track of durations.  That keeps the duration normalized, whereas you'll need to do almost as much work or more to normalize multi-column durations.

Rails (activesupport) also gives you wonderful methods to work with time.  For example, if your duration is in seconds, you can easily add the duration in seconds to a point in time and get an end time:


  end_time = Time.now + duration_in_secs


It is a bit more work using virtual attributes to separate it out, but in my experience, it's not that more work.  perhaps there is a plugin or gem that simplifies it.

How to store length of time in a model with Rails?
From what I understand, citizens of Hong kong (i.e. holders or HK Special Administrative Region passports) do not require a visa to go to Russia for short trips less than 14 days, according to this page. Does it make a difference if that person currently lives in another country, such as Canada, citizens of which - do require a visa to go to Russia? The same person is also holding a Canadian passport.

Does current residency play a role in this matter at all, if the person tries to enter Russia as a Hong Kong citizen?
