You can mouseover to get exact date.
However, 7 days works well for many organizations, others would prefer 2 days (so just limited to minutes ago/today/yesterday/tommorow), a few would prefer month.

Had a request to keep the handy minutes ago but get rid of the 6 days ago.
Can see where if someone reports a problem, they might pulling up a calendar to figure out which logfiles to look at, instead of easy mouseover, or what I would consider easy math like 4 FEB 15 minus 6d is 28 JAN 15 - easily mistaken for 29 JAN 15.

Maybe we just add the ability to show both pieces of information without mouseover. Display absolute date + relative date. A mouseover is something you have to teach people of it's existance; vs a handy, international, sortable in exports:
2015-02-04 13:09 (27 min ago)
or
2015-02-02 13:09 (2 days ago, monday)

Related files for configurable cutoff value: AbstractDateTimeRelativeDatesFormatter DateTimeRelativeFormatter HtmlMetadataManager

Could be made into separate ticket but while on subject, instead of using jira-config.properties allow jira.lf.date.relativize in the admin-ui for easier toggling (jpm.xml requires-restart is false and it could be sysadmin-editable true). i.e. Not everyone has HA/datacenter, if you disable it in one maintenance window, and people demand it back now have to restart again.

This is for read views, for entering information like 'due in 5 days' see other tickets such as JRA-16366