The date format used in SmarterTrack is dependent on the dominant format used by your selected language / locale. To change your date format, you will need to change your Preferred Language in your preferences. To get the date format you specified while using English, switch your language to English (United Kingdom) (en-gb). Be aware that this will have additional side effects: some labels may change slightly, and you may be unable to see some KB and News articles on the portal - specifically if those articles are flagged for a different English locale.