Rick made a good point about checking http://orangeclerk.onetgov.net/
for info on where it stands as far as status. You may or may not know a lot about what you will be reading though. If you would like to stay for as long as possible in this home, I recommend having your landlord renew your lease, if you are there month to month, as it will be a much better way of having the lender let you stay (if it's something they do for tenants).
I have seen lenders allow the tenant to stay for the remaining of their lease. Sometimes even with the current rent they are paying according to their current lease.
To answer your question, there is no set timeframe at all, although the properties I have known about more closely have taken over a year. I know of an aquaintance that has not made a payment on a condo in 3 years and is yet to hear anything else about a foreclosure.