I Live in Las Vegas, and my wife and I are on SS, It seems I can afford the rent 0f 860.00. How many days do we have for eviction

Don't you mean you CAN'T afford the $860 rent?

Do you have a signed lease or are you on a month to month?

As soon as you are late, they give you a pay or quit notice, without looking your exact state it will be about 10 days. After that they can file for eviction in court. This can take about another two weeks.

They can have you out in a month of less if you don't pay

Nevada allows for a 5 day pay or quit notice. So, as soon as you miss a payment, the landord can serve you with such a notice. You then have 5 days to pay or move.

If you don't leave, then the landlord goes to court for an unlawfule detainer notice. This will require a hearing. How long that will take depends on local courts. At the hearing, unless you can show cause why you shouldn't be evicted (and inability to pay is not an excuse) the court will issue an eviction order giving you a few more days to vacate. At that deadline, the landlord can hire a sheriff to physically remove you and your belongings.

What I suggest is you go to the landlord and explain your circumstances. Tell the landlord that you are looking for less expensive lodgings and will move out as soon as you find some. See if you can negotiate a reduced payment with the promise you will pay all that you owe after moving.