17. On Friday afternoon, one should light the Chanukah candles before the
Shabbos candles (1). One must kindle [the Chanukah candles] after "Plag
Haminchah" (2). The afternoon service ("mincha") should be recited first (3).
One must place enough oil [in the menorah] so that the candles will burn
for half an hour after the appearance of the stars (4). If one has not done
so, the blessings recited are considered to be blessings recited in vain
("bracha le'vatalah"). If one lights [the menorah] in a doorway, one should
place something between it and the door, so that the wind does not
extinguish it when the door is opened and closed.
(1) Obviously, all this must be done before sunset, when the prohibitions
of Shabbos begin. One should light the Chanukah candles immediately before
lighting the Shabbos candles, so that one is lighting the Chanukah candles
as close as possible to sunset (without, of course, risking a violation of
(2) "Plag Haminchah" is an hour and fifteen minutes before the appearance
of the stars. This time period is measured according to the concept of
"sha'os zemanios" ("seasonal hours"). The length of each "seasonal hour" is
calculated by totaling the number of minutes from dawn ("alos ha'shachar")
until the appearance of 3 stars ("tzeis ha'kochavim"), and then dividing it
by twelve (some total the minutes from sunrise ("neitz") to sunset
("sh'kia")) (See HY:139:10 for a discussion of the correct time for
lighting Chanukah candles).
(3) If one cannot find an earlier "minyan", one should preferably pray
"mincha" with a "minyan" after lighting the Chanukah candles, rather than
praying beforehand alone (Halachos of Chanukah by Rav Shimon Eider, pg 41).
(4) See HY 139:10 for more details.