How many nights did it take for your LO to finally STTN? We sleep trained my first LO and it took about 3 days if I'm remembering correctly. We are on night two of sleep training our youngest and she screamed for over an hour last night, it was no fun. Maybe I just forgot how it went with my oldest. Im curious how many nights it took for your LO to finally STTN after you went the CIO route.