According to Maran in siman 672, the proper time to light the Menorah on the nights of Chanukah is at Tzet HaKochavim (twilight). So the question is asked when exactly is Tzet HaKochavim? So according to our Minhag, Tzet HaKochavim begins at 13.5 minutes after sunset. So if a person wants to find out the best time to light the Menorah, he needs to find out what time sunset is in his city and then add 13.5 minutes.
I should point out that 13.5 minutes after sunset is the general rule, but we need to adjust that because we are in the winter where the days are a little shorter. So the calculation in the winter time brings Tzet HaKochavim to be at about 12-12.5 minutes after sunset. So therefore one should begin to light his Menorah actually 12 minutes after sunset. That would be the preferred time to light the Menorah.
The light on the Menorah should last at least for 30 minutes. So when using candles, one should use candles that have enough wax to last a half hour. And when using oil, one should make sure to draw on enough oil to last a half hour.
Chacham Ovadia Yoseph asks a very important question in his book Yichave Da’at, in Helek 33, siman 51. His question is about a head of household who is not at home at this preferred time. The head of household typically means the husband, and it is quite common for the husband to be at work way past Tzet HaKochavim until 7:00 PM at night or later. So Chacham Ovadia Yoseph asks in such a case, if the husband should designate his wife to light the Menorah for the family at the preferred time of Tzet HaKochavim, or should the family wait until he arrives home later that night?
Chacham Ovadia Yoseph answers and comes out with a big Hidush, and he says it is better in this case for the husband to appoint his wife to light the Menorah at the preferred time. According to some opinions, it’s questionable if you fulfill the Mitzvah when lighting beyond 30 minutes after Tzet HaKochavim. Now that’s not the opinion of Maran, who says that one fulfills the Mitzvah no matter what time he lights as long as it is before dawn. But it seems from Rambam that the opportunity to fulfill the Mitzvah is gone once 30 minutes after Tzet HaKochavim passes. So in order not to put ourselves in a dilemma, Chacham Ovadia Yoseph therefore says it would be better to appoint one’s wife to light the Menorah at the preferred time.
Now one should be reminded to be conscious of the preferred lighting time especially on Sunday evening. Many people fall into the habit of lighting late when they arrive home from work. So on Sunday night, one should be watchful and take advantage that he is home, and light the Menorah at the preferred time.
To review, the preferred lighting time is Tzet HaKochavim, which in the winter months is about 12-12.5 minutes after sunset. According to Chacham Ovadia Yoseph, Lechatchila it is best for the head of household to be home at that time and light the Menorah for the family. However, if the head of household is the husband and he can not be home until later, it would then be better for his wife to light on behalf of the family at the preferred time.
