You can use "time zone" in double quotes to search for it as a phrase. I do get plenty of results with this phrase.
Since the documentation is based on Mediawiki, it uses that style of search syntax, which certainly has its quirks: https://en.wikipedia.org/wiki/Help:Searching
Since the documentation is based on Mediawiki, it uses that style of search syntax, which certainly has its quirks: https://en.wikipedia.org/wiki/Help:Searching