Entering dates into apps, especially web apps, is pretty bad for something that's nearly ubiquitous. To avoid letting users make mistakes entering data, you have to break the date into field after field after field, each with a pop-up listing valid data.

Here's how Plone does it:

Here's how Lightning, a Thunderbird calendar extension, does it:

There's a lot to like about Lightning. First of all, it's easy to make mistakes when entering time in a 24-hour format. What time is 7PM? Lightning lets me just pick the second line under 7PM to indicate PM.

Second, selecting the minute is more compact and avoids scrolling. Also, times are always in the same place. Not so with Plone. If the long list hits the edge of the screen it will reposition the list. And you have to scroll.

These two benefits come from simply wrapping the data, instead of listing it linearly. Imagine.