The Shulhan Aruch (Orah Haim 672) writes that the proper time to light the Hanukah candles is "the end of sunset," referring to Set Ha’kochavim (nightfall). In New York City, Set Ha’kochavim occurs twenty minutes after sundown. Thus, if, for argument’s sake, sunset occurs this time of year at around 4:30, then the proper time for lighting the Hanukah candles would be at 4:50. One must ensure to provide enough oil for the candles to burn for at least a half-hour.
The Shulhan Aruch emphasizes that one should light no earlier or later than that time. He adds, however, that if one is preoccupied and will not have an opportunity to light the Hanukah candles that late, he may light the candles earlier, as early as Pelag Ha’minha (1.25 Halachic hours before sundown). In such a case, however, he does not recite a Beracha, given the dispute among the Halachic authorities on this point.
If a person did not light at the preferred time, he may still light throughout the half-hour period following Set Ha’kochavim (5:20 PM in the case mentioned above, when sunset occurs at 4:30). If one did not light during this period, he may light at any point throughout the night, but he should ensure that some members of his household – such as his wife or children – are awake so that his lighting achieves "Pirsumeh Nisa" (publicizing the miracle). If a person did not light at all throughout the night, he missed the opportunity to perform the Misva and cannot make up the missed lighting. The next night, he lights the same number of candles as other people, even though he missed the previous night’s lighting.
In Siman 673, the Shulhan Aruch rules that all oils and wicks are suitable for the lighting of Hanukah candles. When it comes to Shabbat candles, Halacha allows using only those oils and wicks that produce a clear, steady flame, because if the flame flickers, one may tilt the lamp or wick to improve the light, thus violating Shabbat. On Hanukah, however, these restrictions do not apply. Even on Shabbat Hanukah, one may use oils and wicks that are not suitable for use as Shabbat lights. Since Halacha in any event forbids making personal use of the light of the Hanukah candles, there is no concern that one may tilt the lamp or the wick to produce a steady flame.
Nevertheless, it is preferable to use specifically olive oil for the Hanukah candles, since the miracle we commemorate occurred with olive oil. If one does not have access to olive oil, he should preferably use either wax candles – which today produce a clear, steady flame – or a different kind of oil that produces a steady flame. As mentioned, one must ensure to use enough wax or oil to sustain the flame for at least a half-hour.
The Kaf Ha’haim (Rabbi Yaakov Haim Sofer, Baghdad-Israel, 1870-1939) rules that one should not "mix and match" different kinds of candles; he should use either oil or wax for all the Hanukah candles, and not use wax for some and oil for others.
One does not fulfill the obligation of Hanukah candles with electric lights; this is the ruling of Hacham Ovadia Yosef in his work Yabia Omer (vol. 3, 35).
