Interestingly enough, my CFI just covered this on my flight review. You can log it legally. According to FAR 61.57

(b) Night takeoff and landing experience. (1) Except as provided in paragraph (e) of this section, no person may act as pilot in command of an aircraft carrying passengers during the period beginning 1 hour after sunset and ending 1 hour before sunrise, unless within the preceding 90 days that person has made at least three takeoffs and three landings to a full stop during the period beginning 1 hour after sunset and ending 1 hour before sunrise, and-

The "1 hour after sunset and ending 1 hour before sunrise" is key here. Now when it comes to logging night time you use the definition of night in FAR 1.1:

Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the American Air Almanac, converted to local time.

So you can lookup the evening twilights and be exact, but as a rule of thumb my CFI said to use 1/2 hour after sunset as a general rule. Which gives you about 1/2 hours to log night time while carrying pax. So if the recorded sunset for tonight is 8:00pm, you can log night time between 8:30pm-8:59pm if you're not current. But after 8:59pm the passengers HAVE to be out of the aircraft (preferably while the airplane is on the ground).