I've heard the theory (whether established or not) that "time" as we know it is man-made and therefore, does not necessarily exist, or was not in existance in the beginning of time (Ironic, I know). That although the sun may rise every 24-hours and continue this pattern throughout the seasons, there is no such thing as time or days. Your life is a "day" then, for days as we know them were created by human kind.
I'd be interested to hear opinions back on this, although I don't have much of a stance on it.