date & time

In our day-to-day life, dates are simple and straightforward - we read them, make plans around them, and share them. Apart from the occasional missed birthday, things go smoothly. But we've been deceived - dates are anything but simple. Here, we look at how to keep our dates local and truthful.

DateFormatters are expensive to build, so we cache them. DateFormatters are useful, so we share that cache. DateFormatters are mutable, so we end up with hard-to-reproduce bugs. Here, we look at how to cache and share DateFormatters without the bugs that come from them being shared mutable state.