Ahh ... a short and sweet authoritative source. All emphasis herein is mine.
Debate Time. Consent agreements that include limitations on time available for debate are also called "time agreements." A time agreement may establish an overall limit on debate of a measure, or may regulate only a certain day or portion of consideration. Usually, it specifies a length of time for debate of a measure, "equally divided and controlled" by the majority and minority bill managers. Occasionally, other Senators may also control blocks of this "bill time," or it may be divided unequally among Senators controlling it. When time on a question is controlled, a Senator can be recognized to speak on that question only when a colleague who controls time first yields a portion of it to the Senator. Also, until all time on a question is used or yielded back, no vote can occur on the question, nor can an amendment or motion to table be offered.Here is a link to CRS 98-225, the general case referred to in the publication linked above.How Unanimous Consent Agreements Regulate Senate Floor Action
Richard S. Beth - Congressional Research Service
As to how the actual practice breaks down, and in particular whether the DEMs took advantage of their majority status to shortchange the minority from debate time, I don't know.
Many thanks for the info...BTW, man could you ever imagine Ev Dirksen on C-span...Lawdie, what a show that would be..