#Mathematica 208 185 139 bytes
Mathematica 208 185 139 bytes
Moves a purple pixel around an array used as an Image.
Method 1 139 bytes
n=900;Dynamic@Refresh[t=DateValue@"Second";ReplacePixelValue[Image@Array[1&,{n,n}],
400{Cos[z=Pi/30t],Sin@z}+450->Purple],UpdateInterval->1]
Method 2 154 bytes
Plots a pixel along a circular path in 60 seconds.
Dynamic@Refresh[t=DateValue@"Second";Graphics[{[email protected],Purple,
Point[{Cos[z=Pi/30t],Sin@z}]},PlotRange->1,ImageSize->Full],UpdateInterval->1]
Method 3 193 bytes
This draws a clock, with ticks and labels in white, for which the second hand is a pixel.
Dynamic@Refresh[ClockGauge[AbsoluteTime[],TicksStyle->White,
GaugeMarkers->{None,None,Graphics[{White,Disk[],Purple,
AbsolutePointSize[.01],Point@{3,0}}]},PlotTheme->"Minimal"],UpdateInterval->1]