24 April 1901
On 24 April 1901 a comet that became known as 'The Great Comet of 1901' or 'Viscara' was visible to the naked eye over most of South Africa. The comet was yellowish in colour and remained visible for the next month (until 25 May). The comet was first spotted by astronomers at the Royal Observatory in Cape of Good Hope, and a certain Mr. Innes was the first person to observe the comet using a 10-inch guiding telescope. Two other people, namely Mr. Lunt and Mr. Hill made further observations, the latter describing the comet in a telegram dated 24 April 1901, stating 'saw a comet this morning at 5 o'clock due East'.
References

Gill, D. S. (1901) The Great Comet of 1901, as observed at the Royal Observatory, Cape of Good Hope [online], Monthly Notices of the Royal Astronomical Society , Vol. 61, p.508.|Cloete, P.G. (2000). The Anglo-Boer War: a chronology, Pretoria: Lapa.