Jewish Law
Daily Halacha - From What Hour is Melacha Prohibited on Shabbat Eve?
Essential guidelines for preparing for Shabbat: when to stop Melacha and what activities remain permitted

From what hour is Melacha prohibited on Shabbat eve?
It is forbidden to do Melacha on Shabbat eve from nine and a half hours [two and a half hours before sunset] and onwards, so that one will be free to attend to Shabbat preparations. One who performs work during this time will not see a sign of blessing from it, and it is forbidden to do so. Regarding haircuts, there is room for leniency to get a haircut throughout the day [Chazon Ovadia 1, p. 42].
Is it permitted to engage in commerce [buying and selling] on Shabbat eve?
Engaging in business is not considered work, and especially stores that sell food and drink for Shabbat - they are permitted to sell until close to the onset of Shabbat [there].
Ach Tov VaChesed - Daily Halacha
