On the Monday after the Sunday of All Saints (tomorrow), we begin a fasting period, in accordance with the Lord's words, "when the bridegroom is taken away from them, then shall they fast." This fast is called the Apostle's Fast because it lasts until the Feast of the Holy Apostles Peter and Paul, on June 29 / July 12.
As is usual, the fast consists of abstinence from meat, fish, dairy products, eggs, olive oil, and wine (alcoholic beverages). On Saturdays and Sundays, as well as on Thursday June 7th (in honor of St. John the Baptist), the fast is relaxed and we may consume fish, wine and oil. On Tuesdays and Thursdays, as well as on Wednesday June 6th (in honor of St. Symeon), we may use wine and oil.