Why is it called on the dot?

Why is it called 'on the dot'?" I pondered, brow furrowed in confusion. The term seemed to carry a certain air of precision and punctuality, yet its origin remained elusive to me. Was it a reference to some ancient timekeeping device, perhaps a clock with a dot precisely marking each moment? Or did it stem from a more modern context, where digital displays and exact timing have become the norm? I imagined myself standing in a bustling financial district, surrounded by the flurry of activity and the constant ticking of clocks. Perhaps, in this fast-paced world of finance, 'on the dot' had become a shorthand for being exactly on time, for adhering to the strict schedules and deadlines that govern the industry. But still, I couldn't shake the feeling that there was more to the story. Was there a deeper meaning behind this seemingly straightforward phrase? I resolved to delve deeper into its origins, hoping to uncover the hidden wisdom behind this mysterious moniker.