https://vombat.tumblr.com/post/60530544401/date-parsing-performance-on-ios-nsdateformatter-vs
Many web services choose to return dates in something other than aunix timestamp (unfortunately). […]Luckily for us, SQLite is quitegood at parsing some ISO-8601 dates and works blazingly fast.
Very handy tip. Works about "1400% faster" than NSDateFormatter, according to the tests in the post.