Getting a sum of durations in rails

For my “I had trouble finding this on google” series, here’s a solution I found to getting a total duration from a collection of objects with durations stored as Time objects.

total_duration = durations.reduce(Time.gm(2000)) do |total, time|
  total += time.to_i
end

There are two little tricks happening here. The first is that durations are stored as a time of day on January 1st, 2000, so we use that as the reduce seed. The second thing is that the Time class defines addition for integer objects, but not for other times, so you have to convert your duration to an integer first.

No rocket science here, but a couple little quirks that made it a little harder to add two times together than I expected.