Relative time displays (e. g. in 3 days). It is a nice feature. But there can be dates where it is important to see the exact date and time. For instance flight datetime. It is a pitty that this feature can only be disable globally (https://confluence.atlassian.com/display/JIRAKB/Disable+relative+dates+in+JIRA+applications).
My suggestion and wich is to makes this configurable per custom field or field configuration, whether relative dats should be displayed or not. E. g. as option in in field renderer which seems *not *to be available for date custom fields now.