This is the data I recorded for the fishless cycle I did in Jan 2016

Because this tank is 26 litres and has just one male betta and one small nerite snail, I initially added ammonia to just 1 to 2 ppm as this is more than enough for that bioload. The colour was between 1 and 2.

Day 1 - added ammonia Stage #1

Day 4 - no change

Day 7 - no change

Day 10 - no change

Day 13 - no change

Day 16 - ammonia still same but just a hint of nitrite though still well below 0.25

Day 19 - same as day 16

Day 21 - ammonia still showing between 1 and 2 and nitrite the merest hint. Got frustrated and did a 100% water change then added ammonia to give a reading between 2 and 4 ppm.

Day 24 - ammonia between 1 and 2, nitrite 0. The ammonia dropped from 2 - 4 to 1 -2 but no idea where it went.

Day 26 - tested after 2 days because getting fed up. Ammonia 1 to 2. Nitrite merest hint.

Day 28 - ammonia 0.5 nitrite > 5 (off the top of the chart). Added ammonia to ~ 3ppm Stage #6

Day 30 - ammonia 0, nitrite >5

Day 32 - ammonia 0, nitrite >5. Zero ammonia on 2 test 2 days apart, added the one third dose of ammonia. Stage #8

Day 34 - ammonia 0, nitrite >5

Day 36 - ammonia 0, nitrite >5. Zero ammonia in 2 tests 2 day apart, added the one third dose of ammonia Stage #8 again

Day 38 - ammonia 0, nitrite >5

Day 40 - ammonia 0, nitrite >5. Zero ammonia on 2 tests 2 days apart, added a one third dose of ammonia. Stage #8 again

Day 42 - ammonia 0, nitrite 0. Added a 2 to 4 ppm dose ammonia Stage #10

Day 43 - ammonia 0.25, nitrite 1.0

Day 44 - ammonia 0, nitrite 0. Added 2 to 4 ppm ammonia. Stage #10 again Then power went off for 4 hours.

Day 45 - ammonia 0, nitrite 2 - was the cycle affected by the power cut?

Day 46 - ammonia 0, nitrite 0. Added ammonia to 2 to 4 ppm Stage #10 again

Day 47 - ammonia 0, nitrite between 0.5 and 1. Added ammonia to between 2 and 4 ppm Stage #10 yet again

Day 48 - ammonia 0, nitrite 0. Finally stage #14

Ammonia and nitrite both zero 24 hours after adding full dose ammonia = cycle finished.

As you can see, ammonia finally dropped on day 28. And nitrite dropped from off the top of the chart to zero between days 40 and 42.