*sigh* It's not that complicated:
4 Months ago: * Explosion on top of NY
* Peter took Nathan to hospital,
* Peter got captured.
* Angela told Heidi about how the Petrelli boys are all crazy. This is the point where Heidi considered her options. I assume she started to move out and prepared a divorce paper at this stage (even though she probably didn't tell Nathan because he's still in the hospital).
1 month ago: (or 3 weeks ago depending on how accurate Bob's time estimate was)
* Peter and Adam escaped from the company.
* Peter and Adam healed Nathan in the hospital.
* Peter encountered Elle/Haitian.
* Peter got packed into the container
* Nathan regained his consciousness
* Nathan got served with a divorced paper by Heidi
* Nathan starts becoming drunk/grow beard. In other words, he had at least 3 weeks to grow beard/turned to alcohol. Not too much of a stretch, I know some men who have grown beard in 2 weeks.
Episode 1: (aka 1 month or 3 weeks after Peter escaped)
* Nathan continues to booze his day/night to dull the emotional pain
* Peter finds himself in Ireland still trapped in the container.
Episode 4: (possibly a few days/weeks after episode 1)
* Nathan sobers up and teams up with Matt
QUOTE
What I find strange is that Nathan was apparently healed by Adam three months after the explosion, and had already grown a giant mountain man beard and developed a drinking problem severe enough he could need to go into rehab three weeks later when the season started!
When a person starts drinking, there's a likelihood that they become addicted to alcohol. However, this is not always the case. Just because Nathan was drinking everyday, it doesn't mean that he's an alcoholic. Especially not when he managed to sober himself up to bail out his mother from jail. It seems to me he was still in complete control of his life...except when he chose not to. Angela was most likely just overstating the need for Nathan to go to rehab just to be sure. But it doesn't mean that he actually needs that rehab.