Hi there, I’m on day one of NAP training. We started sleep training last night. My 6 month old son only cried 18 minutes before he fell asleep for the night. This morning‘s nap he only cried for eight minutes and slept for two hours, the next nap he cried for 10 minutes and slept for 45 minutes. His 3 PM nap however – he has been crying the whole entire time. I know that I am to keep him in the crib for an hour without check-in’s but how long is it safe for him to cry?