The question says it all, how much time as passed from the start of the Zombie outbreak to the start of Season 3?
Using Laurie's pregnancy you can say "around 9 months" but we don't know if she became pregnant before or after the fall, and if after how long after.
Is there a canonical answer? Possibly something from the comic books?
I've no real reason for asking other than me & the missus are curious.
Thanks,
According to Axel in S3E02 (Sick):
they had been locked in the cafeteria for 294 days (9.6 months).
It's unknown if they were locked in at the initial onset of the outbreak or if it was a day or two later.
Hershel's farm ended at some point in early fall (as there was no mention of a harvest being performed, yet nights were cold.)
The members of the group repeatedly mention "Through the winter" in reference to their time traveling since the Farm. Also, Lorrie's pregnancy was already several months along when the incident occurred.
From this I would guess they left the farm in early September and arrived at the prison in march. But again, this is just based on my own estimates with the evidence given.
With Axel's count of 294 days since the prison riot that would put the events of the first episode (with Lorrie's conception by either Rick or Shane being at about that time) to be about 3-6 weeks after the prison riot.
