Need help explaining why "had an operating period" needs "of" on the end

Question

In a large set of reports I'm editing that use boilerplate text repeatedly, I'm stuck with the phrase "had an operating period from [Date] to [Date]." However, I could change it a little if I could prove the grammar is wrong.

I think "had an operating period" requires "of" at the end (had an operating period of X).

And a date range requires both "from" and "to" (so we cannot pilfer the "from" that belongs to the date range and use it as the end of the "had an operating period" phrase).

I believe I must add "of," so the phrase would read "had an operating period of from [Date] to [Date]."

Algebraically, the phrase would be "had an X of Y."

X = "operating period" Y = date range

But I don't know how to explain why the "of" is needed. Can anyone help?

Again, I know "of from" sounds awkward. It would be better to rewrite the sentence, for instance, "The operating period was from [Date] to [Date]" or "Operations took place from [Date] to [Date]." But rewriting is not allowed in this case. I just have to have a convincing argument for why the "of" is needed grammatically. By the way, I already got an answer from a CMOS editor, and she or he disagreed with me (because of the way "of from" sounds, but no formal reason was given).

Answer 1

I agree with your CMoS correspondent that mixing the two forms doesn't sound good. As such, my answer doesn't attempt to justify your use of "of" with "from ... to".

When you define a period, you can use either a duration (e.g. a week) or the two ends of an interval, as the examples in the following definition show:

period noun 1 A length or portion of time. ‘After all, a new president enjoys a honeymoon period of three months at most.’ ‘the period 1977–85’ - ODO

The period of X form indicates that X is the duration. The period from X to Y form defines the period to start at X and finish at Y.

Note: if you mix the two forms, you end up with a range of durations, as WS2 notes. For example, the "period of from X to Y" indicates that the period may (is allowed to) be of duration X or duration Y or any duration in between. It doesn't mean the period starts at X and ends at Y.

Answer 2

'I had a bus pass lasting from X to Z' can be followed by 'but I lost it [on date] Y'; 'I had a bus pass from X to Z' can't (unless you find it again).

The 'lasting' or 'of' indicates the period of the availability / contract / validity etc; dropping it shifts the default sense to the period of actually 'having'. There may be little difference in your case.

Preposition deletion is tricky, and though often leading to an idiomatic variant, isn't guaranteed to do so.

'Lasting' sounds less clumsy here, as WS2 probably agrees.