For a normal fish-less and maybe a few flakes or pellets type of cycling, it took me about 6 weeks. Few weeks more than freshwater.
Add some beneficial bacteria, and since u are at nitrite state, use microbe lift nite - out II. It contains nitrification bacteria which is what your tank is cultivating now. Follow dosage and add more doesn't harm. It speeds up cycling very fast.
Freshwater takes about 4 weeks for full cycling to complete, my personal experience with that product + OF beneficial bacteria, speeds up freshwater cycling and completes in 1 week.
With freshwater, it took me about 2-3 weeks with such products to complete cycling. If you are not adding anything, 1 mth isn't enough.