I think that different publishers update their guidebooks at different intervals, and even for the same publisher, the updates may come at different intervals for different destinations, depending on need. I would look at the copyright page, where the dates (usually the years) of previous editions are listed. There you might see, for example, that the guidebook has been updated every 3 years. If that is the case with DK Eyewitness Toronto, then you might guess that the next edition may be coming out in 2016. But if it’s been updated every other year, and you’re not going until next year, you may want to wait for the new edition.

I really doubt they update every year so I think you are safe buying the 2013. I often use guidebooks that are 5+ years old, just borrowing from the library. I supplement that with doing research on tripadvisor and calling or emailing the city directly. The tourist bureaus usually will mail out a map and their brochures.

On a Thursday, usually in the afternoon between 2 – 3:00 pm.

No, on a more serious note, I agree with @JLeslie. Many of the guide books I purchase are a few years out of date but I use them as a guideline for further online research. They make a good initial source for suggestions of places to go, people to see and things to do.

Also, I have found that if you buy the ones 10+ years out of date you can get them really cheap (many times the older ones are in the clearance sections) and you will will find suggestions for things that were once popular and may still appeal to you but that will not have the throngs associated with those purchasing this years copy, including places to stay that are nice but not trendy anymore.

Don’t buy one. Use your tablet or smartphone, which is far more likely to be current.