Most form generators allow you to choose width of the field but it appears not to be the case in DF. It determines the width of the field (in Entry mode) by taking about 60% of the longest field value.
I was able to sort of fix the Time field stretch by selecting "Mask" in Settings, which put M, D and Y on top of one another, and thus not causing it to crowd into the adjacent field. This action also removed the "Enable" check box upon create.