which is better

[mary joe]

- One month of delay
- A month of delay

Which is correct?

[Teia]

Originally Posted by mary joe

- One month of delay
- A month of delay

Which is correct?

What is the context ?

A month of delay - correct

one month delay. - correct
, or

month-long delay [for more months than one : two - month delay, five-month delay , etc.].

e.g.
Each additional month of delay increases the amount of taxes.
The police requested a three-month delay to review the evidence.

[mary joe]

So, a month of delay/ one month of delay is okay so long as I finish the research. [Both are correct?]

[Anglika]

(There will be) a month's delay in the completion of my research would be better if what you are doing is notifying someone that you have not finished.