The trouble with “night” is that the way the FAA treats what we consider night changes. It’s used a bit different for position light requirements, “night” landing currency, and general use. We sometimes talk about “night” having multiple FAA definitions. In reality there is only one FAA definition of the word, which appears in FAR 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, when the word “night” is used in a regulation, this is what it means unless the regulation says something different. So, for general logging of night flight time for certificate requirements, including the landings, I would use this definition. I would also use this definition for all FAR purposes, like night VFR visibility requirements, fuel reserves, etc.
For “night” passenger-carrying currency purposes, we’re talking about the regulation saying “something else”, in this case 1 hour after sunset to one hour before sunrise (61.57). But that time frame limitation describes a certain part of the “night.” It doesn’t have any effect on the overall definition of “night”. And it only applies to currency requirements for carrying passengers as PIC during a certain part of the “night”. It doesn’t apply to anything else. Finally, there’s the aircraft lights rules from 91.208, requiring lighted position lights “during the period from sunset to sunrise” (different in Alaska). That regulation doesn’t use the word “night” at all.
Oh, one more thing. Most of us don’t carry around the American Air Almanac (in fact, I don’t even know anyone who has seen one!). The next best choice is the U.S. Naval Observatory web site