Illuminated clock dials were first permanently exhibited in London in 1827.

In the Gentleman’s Magazine for 1826 a writer suggests that an illuminated clock dial has been long needed in the great metropolis.

Liverpool, Manchester and other provincial towns already had such clocks, but London had not been able to boast of this accommodation.

The church wardens of St. Bride’s determined on setting the example, and by way of experiment placed a glass dial in the centre intended for the clock, behind which a powerful gas conductor was fixed and the rays of light reflected on the face of the clock made the points of time as distinctly visible as they are at St. Paul’s at noon. The same magazine for 1827 later reports that “such is the mechanical ingenuity

displayed that the clocks by their own revolution light themselves as soon as the sun sets, and extinguish the lights the same when the sun rises, and this throughout the year whether the days are long or short.”

 
(Wood’s Curiosities of Clocks and Watches)

Must be magic…