Q: When does Foundation take place? I'm currently on the third Foundation book ("Second Foundation") by Isaac Asimov, and I'm beginning to wonder when does this series take place. I know 1FE is 12069GE, but what would that be in AD/CE? Is there any indication as to when the series takes place?
This Amazon review claims it is "allegedly 50,000 years" in the future. Is there any basis for this or would stating the year be pure speculation?

A: It's more like 25,000. Have a look at this handy timeline. The high points are that the Robots universe and the Foundation universe are one and the same. Additionally, there are 3 different eras that passed. The early US robotics stories basically take place in what is now modern day and the rest of the timeline is built from there. Please note that some of these dates may be off on the era transitions, since those are the hardest to pin down. Also, spoilers are scattered throughout.

A: According to Johnny Pez's Insanely Complete Fiction List hosted on my site, with permission, Second Foundation started at 316 FE / 12384 GE / 23968 AD. I'm not sure why Johnny and Attila (link posted by sarge_smith) determined different dates. The advantage to Johnny's list is that he lists all the plot points he used at the bottom of the timeline, so there is really no danger of major spoilers. Also, Johnny's list includes all of the expanded universe (Robot City, Robots & Aliens, Caliban, etc) authorized by Asimov and written by other authors shortly before his death.
Asimov states clearly in one of his introductions that he did not originally plan for the Robot & Foundation Universes to be together. I was looking for the reference, but was unable to find it. This Wikipedia article suggests the universes were tied together in Foundation's Edge.
I'd like to note that that the bottom of the repost of Attila's list is the mention of a book called "Psychohistorical Crisis" which does not fit into the Robot & Foundation canon. The book appears to have some good reviews, so I might check it out sometime.

A: Long ago in the mid or late 70s there was a Terminus in 23,309 Worldcon (Galacticon?) bid announced with an opposing bid from Trantor.  I'm not sure exactly how the date was arrived at, but I suspect that Asimov was consulted. If not, dates like that were certainly part of the common lore of fandom at the time.

A: It probably comes from Pebble In the Sky, where Schwartz' English is described as a prehistoric language found "in fifty thousand year old strata" on worlds in the Sirius Sector. 
However I'm not so sure if the later books are consistent on this, as PitS also speaks of two hundred million planets" in the GE, whereas in Foundation there are only twenty million. They might disagree about the calendar also.  
