Time - the experience of length of time is imagined linear but the charting of the time passing is circular - the clock, the months, the year/orbit.

And so not surprisingly in the words of Dr.Who: “People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint - it’s more like a big ball of wibbly wobbly… time-y wimey… stuff.”