When you mouseover a "3 hours ago" time, you get the exact timestamp.
Here's an example of what I get -- the code says:
<span title="2009-07-20 23:12:37Z" class="relativetime">Jul 20 at 23:12</span>
And the tooltip says:
Does this mean the code doesn't know what my timezone is? (NZST, as it happens) If so, what timezone is that time in?
EDIT: Wiki says:
The UTC time zone is sometimes denoted by the letter Z – a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time. This is especially true in aviation, where Zulu is the universal standard. This ensures all pilots regardless of location are using the same 24-hour clock, thus avoiding confusion when flying between time zones.
All I can say is: "That's news to me". Is Z really more common than UTC or GMT amongst people who don't fly planes or steer boats?