Getting baby to sleep in longer, suggestions?

It might be a phase that he is going through. Is he teething? That will make him wake up earlier. My son used to sleep for 9pm to 9am, not anymore. He started waking up earlier when he started getting his molers, he hasn't slept the same since. Sometimes when my son wakes up early I pull him into bed with me and we both go back to sleep. He tends to sleep better that way because he can feel my warmth and heartbeat. Maybe try giving him some formula or milk sometimes that helps to put them back to sleep. The other thing I do is lay down next to his bed and close my eyes and pretend I'm sleeping. Sometimes you have to lead by example, if he sees that your still sleeping he might get the hint that's it's not time to get up yet. I hope you find something that works because I know how frustrating it can be.