Time seems simple until a background job vanishes during the DST switch or an API silently shifts dates because it assumed UTC. We’ll look at why time is genuinely weird, and then work through practical patterns for handling it safely in Ruby and Rails.

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Senior developer at thoughtbot working from Paris. I love Ruby and astronomy, so I created the gem Astronoby which calculates astronomical data and events. I started coding 15 years ago, with more than 10 of those years using Ruby. When the computer is off, I like fermenting stuff and playing bass.