The phrase "agreed upon dates" is correct and usable in written English.
It can be used when referring to specific dates that have been mutually accepted or confirmed by all parties involved.
Example: "We will proceed with the project based on the agreed upon dates for each phase of development."
Alternatives: "mutually accepted dates" or "confirmed dates".
Buffett will sup with the winner and seven friends in New York City on a mutually agreed upon date in the spring of next year.
The Sage of Omaha will lunch with the winner and seven friends in New York City, on a mutually agreed upon date in the spring of next year.
The money that is raised will be held until the goal is reached or until an agreed upon date.
They would meet in the exact midpoint between their two locations, the middle of a pond located in the southern Czech Republic, and not communicate again until they saw each other there at high noon at an agreed upon date.
When I emerged unharmed a week later in Vietnam, I forgot to call home on the agreed upon date and my poor mom spent several days distraught, waiting by the phone, refusing to leave the house (at that time we had no e-mail, no Facebook, just expensive calling booths).
I give my moving company (Shleppers Moving & Storage) a lot of credit for making the move happen on the originally agreed upon date despite all that had happened (and with needing to find a route from Brooklyn to mid-town Manhattan that was passable).
(The six-month timetable turned out to be overly optimistic; the agreed-upon date, March 31st, came and went amid protracted negotiations over security guarantees for the guerrillas).
If A.A.A.A. is unable to deliver your property on the agreed-upon date, A.A.A.A. will store your property until such time as a delivery can be made.
The whole enterprise was recently put in peril when his landlord tried to evict him because he did not open on an agreed-upon date, which was 18 months ago.
