There are two types of Outlook users: those who like seeing relative dates and those who don't. Jim doesn't like it:
I hate this trend of hiding data, using relative dates, etc. None of it works for me at all. Not just annoying, but reduces my efficiency tremendously.
I happen to like it, but anyone who doesn't like it can change the format used in the message list.
To change the date in the Received column in Outlook 2010 or 2013, go to View ribbon > View Settings > Format Column. Select Received on the left and choose any format from the Format list. You can also access this dialog in any version of Outlook by right-clicking on the row of field names and choosing View Settings (Custom in older versions) then Format Columns.
Some of the formats in the list are based off the long or short date formats set in Windows, so if you don't see a format you like, check your Windows date formats.
The Group headers (Today, Yesterday, Thursday) can't be changed but you can turn off grouping to get rid of the groups.
Published February 6, 2013. Last updated on September 21, 2015.