One may not begin to eat within half an hour before candle-lighting time, which is at tzeit (as we will explain below, 13:4). One may not even begin a light meal, since he might drag out the meal and forget to light candles. In addition, one may not drink alcoholic beverages, but one may eat as many fruits and vegetables as one desires. One may even eat bread or mezonot (grain-based foods aside from bread), as long as he eats less than a keveitza (an egg’s bulk; c. 50 ml).
Likewise, one may not begin any type of work during the half-hour period before candle-lighting time that may drag on for a long time, nor should one go to sleep during that time. One may begin to eat, work, or sleep during this period if he asks a friend to remind him to light on time. Nevertheless, even if one begins these activities in a permissible fashion, i.e., more than half an hour before candle-lighting time, he must stop at tzeit and light the candles, so that he does not miss the time that the Sages enacted (mb 672:10; sht ad loc.; Peninei Halakha: Prayer 25:9).
One who is in the middle of work and cannot get home in time to light at tzeit may continue working until he is finished. However, he must take care not to eat until he fulfills the mitzva. In addition, if his work is the kind that can drag on for a long time, to the point where there is a concern that he will end up forgetting to light the candles, he may continue working only if he asks a friend to remind him to light when his work is done (see below 13:6, 9).
One may not even study Torah once the time for lighting the Ĥanuka candles arrives. However, if a regular Torah lecture takes place at that time, and it would be difficult to reschedule it for another time, it is best to keep the lecture at its normal time and remind everyone at its conclusion to light Ĥanuka candles (see below ch. 13, n. 13).