Recently the cache methods started getting uppity about the date_default_timezone_set() not being set. I have fixed this and have updated the phpYahoo class.

phpYahoo v2.1.0.1 Downloads: 279 times

date() [function.date]: It is not safe to rely on the system’s timezone settings. Please use the date.timezone setting, the TZ environment variable or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected ‘America/Los_Angeles’ for ‘PST/-8.0/no DST’ instead