Both are correct but worded awkwardly. Try this: I hope we can finish it by the end of these two days.

The verb tense used here is not common in English, so it is hard to know exactly what you mean. I would say: 1. I hope we can finish it in a few days. 2. I hope we can finish it in 2 days. These sentences are ambiguous, but context will make the meaning clear. They could imply that the speaker will start now and work continuously. But they could also mean that the speaker will start later, but the speaker still hopes to finish before a few days have elapsed. I hope this helps.