Sundial for Sasolburg, Vanderbijlpark, Vereeniging

Note that the "squares" on the diagram must look square, ie one unit of length horizontally must equal one unit of length vertically.

The data used to create this sundial are listed below, if you want to make your own large "walk-on" sundial. The columns are:

• Time: time at each marker on the timeline.
• Xtime: X (horizontal) offset from 0.0 (centre of graph) of each time marker.
• Ytime: Y (vertical) offset from 0.0 (centre of graph) of each time marker.
• Date: Date of each marker on the date line and analemma ("8")
• Xan: X (horizontal) offset from 0.0 (centre of graph) of each date marker on the analemma.
• Yan: Y (vertical) offset from 0.0 (centre of graph) of each date marker on the analemma; this is equal to the Y offset for the dateline. The X values for the dateline are 0.0.
• Teqn: The offsets of time correction scale at the foot of the analemma, in minutes. -15 means the Sun is 15 minutes late (e.g. in February), so 15 minutes must be added to the time read from the shadow crossing the timeline when standing on the dateline. +15 means the Sun is 15 minutes early (e.g. in early November), so 15 minutes must be subtracted from the time read from the shadow crossing the timeline when standing on the dateline.
• XTeqn: X (horizontal) offset from 0.0 of the time correction at the foot of the analemma. The Y value is set to place it conveniently below the analemma.

       Sasolburg, Vanderbijlpark, Vereeniging Area

        Time       Xtime       Ytime        date         Xan         Yan        Teqn       XTeqn
       05h00       2.389      -0.341       Jan01      -0.040       0.951      -15.00      -0.164
       05h30       2.465      -0.198       Jan15      -0.101       0.868      -10.00      -0.109
       06h00       2.498      -0.052       Feb01      -0.149       0.697       -5.00      -0.055
       06h30       2.489       0.095       Feb15      -0.154       0.512        0.00       0.000
       07h00       2.437       0.240       Mar01      -0.135       0.307        5.00       0.055
       07h30       2.343       0.381       Mar15      -0.099       0.094       10.00       0.109
       08h00       2.210       0.515       Apr01      -0.044      -0.168       15.00       0.164
       08h30       2.038       0.641       Apr15      -0.001      -0.375                        
       09h00       1.832       0.756       May01       0.033      -0.594                        
       09h30       1.594       0.857       May15       0.040      -0.756                        
       10h00       1.329       0.945       Jun01       0.025      -0.901                        
       10h30       1.041       1.016       Jun15      -0.004      -0.961                        
       11h00       0.736       1.069       Jul01      -0.039      -0.955                        
       11h30       0.418       1.104       Jul15      -0.065      -0.886                        
       12h00       0.092       1.121       Aug01      -0.067      -0.733                        
       12h30      -0.235       1.118       Aug15      -0.050      -0.555                        
       13h00      -0.557       1.096       Sep01       0.000      -0.334                        
       13h30      -0.871       1.055       Sep15       0.051      -0.128                        
       14h00      -1.169       0.997       Oct01       0.112       0.115                        
       14h30      -1.448       0.921       Oct15       0.154       0.325                        
       15h00      -1.701       0.829       Nov01       0.179       0.567                        
       15h30      -1.926       0.724       Nov15       0.169       0.739                        
       16h00      -2.117       0.606       Dec01       0.119       0.890                        
       16h30      -2.273       0.477       Dec15       0.055       0.959                        
       17h00      -2.389       0.341                  -0.040       0.951                        
       17h30      -2.465       0.198                                                            
       18h00      -2.498       0.052                                                            
       18h30      -2.489      -0.095                                                            
       19h00      -2.437      -0.240