Presenting date and time in a table where time is sometimes (but rarely) needed

Question

I'll try to minimize the rubber-ducking; I'm posting this as a proxy for my team.

We're designing summary table that shows work history of a part (on a mechanical machine). It's intended as a quick reference which appears as a modal.

The users would occasionally like to be able to see the action's time in order to correlate it to some event on the shop floor, but the date is the primary reference.

The original design called for the time to follow the date. This causes an undesirable visual grouping effect and clutters the table with rarely-needed information:

^{download bmml source – Wireframes created with Balsamiq Mockups}

A following iteration suggests using a circle-i tooltip icon which, on hover, will display the time:

^{download bmml source}

There are two concerns with this design:

1. Our users are heavy keyboard users, so a tooltip, while perfectly accessible, may be undesirable (annoying);
2. It does tend to attract the eye to the least important element of the table.

The application is designed solely for desktop computer with keyboard, and mouse as the primary pointing device.

While there are many excellent questions on formatting date and time displays, we're struggling for a good way to show partial date with additional information which is both subtle and accessible.

Answer 1

I will answer my own question for completeness, but please feel free to continue to contribute ideas if you come across this in future.

We decided to show only the date in this view and made the row clickable. Upon clicking, it opens a modal with an excruciatingly complete set of data for that work event.