Timezones are a problem there. Unless you're a hyper-local site, your worldwide visitor numbers will skew anything on a "daily" basis. For example, my blog is

Timezones are a problem there. Unless you're a hyper-local site, your worldwide visitor numbers will skew anything on a "daily" basis. For example, my blog is based in the UK but gets a substantial proportion of visits from the USA - which itself has multiple timezones.