Can't adjust date/time in FCPX

Luis is correct. It takes the Date/Time of the underlying clip. I can't see what the title shows in the viewer.

You cannot modify the date/time of the video clip in the Timeline. It has to be modified in the Browser. Select the project clip and press Shift-F to go to the same place in the Browser clip. Change the date/time from the Modify menu, and it will also change the date/time of the clip in the Timeline, which will be reflected in the title.

I am away from my mac now, so I can’t check. I don’t recall if one can change it, or if it picks up its value from the underlying clip; but if you can change it, I believe it has to be in the Title inspector, not the Info inspector. Click the icon with a T at the top of the inspector, and see if there are any parameters to adjust there.

That menu is for adjusting the date and time of clips. Any change you need to do to a title should be done in the Inspector.