To remove the Server Login time stamps; just edit your DDO 'UserPreferences.ini' file. Find the text section: [User_1].
For example using file: UserPreferences.ini (within /Dungeons and Dragons Online/ folder - same one where your DDO screenshots go depending upon your OS)
Code:
[User_1]
UserName=your_login_name
WorldName_1=Thelanis
LastPlayed_1=2016-09-24T00:04:00
UserFileName_1=en-DDO-EULA-Turbine-html
UserAckTime_1=2013-11-14T14:13:00
UserFileName_2=en-DDO-TOS-html
UserAckTime_2=2013-11-14T14:13:10
WorldName_2=Lamannia
LastPlayed_2=2016-09-01T12:00:00
It should be safe to delete that specific text under the UserName line, and the game will rebuild those login lists when you you login to a specific world. Your list will look slightly different (i.e. Worlds/times listed) but you just need to delete ALL those text lines entirely which are below UserName. Taking care you only delete those lines and not other sections then save the file.
Then try running the DDO client as normal, you possibly won't need to reboot the PC first, after saving the file changes but it never harms.
Do NOT delete [User_1] or UserName=your_login_name of course your own login name will be there not the place holder in my example.
Of course make a backup copy of the file first and ONLY delete the lines I've mentioned.