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).