The LATEST TIME for bringing in Shabbat corresponds to 18 minutes before sunset.
During summer, according to custom, Shabbat is brought in EARLIER in most
centres. This is the time when the traditional Community Shuls recite
"Mizmor Shir Leyom HaShabbat" thus accepting Shabbat (approximately 15
minutes after the beginning of Kabbalat Shabbat).
It should be noted that there is also an EARLIEST TIME for candle lighting,
known as plag hamincha (1.25 relative hours before sunset), which is of little
concern in most centres. However, due
to the late sunset in the Western and Eastern Cape during the
summer months, awareness of this earliest time to light Shabbat
candles is most signifcant.
For more information and for zmanim for specific locations,